


Three Bones and a Baby

by Rehlia



Category: Undertale (Video Game)
Genre: Accidental Baby Acquisition, Alternate Universe - Babies, Brotherly Affection, Dad Sans, Fluff, Fluff and Angst, Gen, Grief/Mourning, It Gets Better, Mentions of Death, Mentions of Violence, Minor Alphys/Undyne, Realistic depictions of how dang hard it is to care for a baby, Sad with a Happy Ending, Sans doesn't like the baby much initially, Single Parents, Slice of Life, Swearing, baby frisk, don't treat a baby like this is what I'm trying to say here, he also has no idea what he's doing
Language: English
Status: Completed
Published: 2017-09-15
Updated: 2018-03-16
Packaged: 2018-12-30 03:59:40
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 13
Words: 66,583
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12100248
Author URL: https://archiveofourown.org/users/Rehlia/pseuds/Rehlia
Summary: Sans didn't expect to find the door to the ruins open. He didn't expect to find a human corpse, piles of dust, and a lone living human baby inside. He sure has hell didn't expect ending up taking care of it. What does he know about babies, anyway?But a promise is a promise and this one has to be kept.No matter what.





	1. Fallen Down

**Author's Note:**

> Happy Undertale Anniversary! 
> 
> Will probably update once a week or once every two weeks, depending.

The door was open. 

Sans hadn’t approached yet. The wrongness of it stopped him in his tracks, preventing him from coming closer. The door to the ruins had never been opened before, and the silence behind the open doorway felt foreboding. Behind the open door, swung outwards and obscuring the camera that he knew to be hidden next to it in the bushes, he could see nothing but darkness. 

He wasn’t sure if that was what it usually looked like in there, but - 

He stopped. 

Stopped thinking, paused his every movement, and listened. 

There was a tiny noise, barely audible. Something soft, a wail that didn’t quite make it there. 

Sans approached the door carefully, slowly, magic at the ready. A single flick of his fingers would send rows and rows of bones forwards, crashing into any potential attacker that might come out of the ruins. He wasn’t normally the type for instant attacks, but… humans came from the ruins. Always from the ruins, that’s why there were so many sentry stations here, so he felt the caution was warranted. You never knew, with humans. The noise repeated, but there still wasn’t any movement in what he could see of the room behind the open door, so he continued his approach until he stood in the doorway. It was dark in here, only a single patch of earth in the middle of the room illuminated by faint sunlight filtering through a far away crack in the mountain ceiling above him - 

He heard the noise again. 

Jumped back, swept his eyes over the floor of the room, and finally saw.

Saw the corpse. 

It was in a pretty bad shape, looked burned. Smelled burned. Ew. Humans were so disgusting, leaving so much behind instead of a clean heap of dust.

It wasn’t that he wanted to, but corpses didn’t wail, so he crouched down to get a better look. Checked for a soul. 

There wasn’t one left in the corpse, _dammit_ , it would have been the last - 

Behind the corpse was a bright red soul of determination. 

Sans shifted, leaned forwards to see, and saw the other human. 

It was more of a lump, really. 

A small, fleshy thing, rounded cheeks and a rounded body with stubby limbs and a small patch of hair on its head, clad in a blue and purple striped onesie. Its eyes were scrunched up close and its mouth open, heaving quietly for air, the belly rapidly expanding and contracting. Huff, huff, huff, _wail_. It was still not quite a wail though. More of a whimper. 

“welp,” he said.

The baby whimpered again. 

Sans rose slowly from his crouched position, looking around once more. There wasn’t anything else in here but the corpse and the baby. 

“welp,” he said again, just for good measure. Allowed the magic he gathered to form into a single sharp bone. 

The last human soul, finally. He’d better be quick about it, not that a few more moments mattered much in the grand scheme of things, after one thousand years of banishment under a mountain, moments were practically nothing, but still. Why wait? The soul they needed was right there, and dragging the collecting out felt cruel. He wasn’t cruel. He was a sentry, so he was going to do his job, quick and easy. Then Paps wouldn’t have to see this mess - _wouldn’t have to be the one to do it, would never have to be the one to do it, they would be out and collecting human souls would no longer be a thing, and his brother’s innocence would be safe_ \- and they were all going to get out. 

He stepped around the corpse, stepped closer to the baby, and raised his bone. 

He thought of his promise. 

Did it count though? The human hadn’t come out of the door, had it? It was still in here. And they’d be free, all of them, out of the mountain - 

But he still had that voice ringing through his head, the sincerity and integrity in it, the desperation. A voice he hadn't been able to deny.

He really hated making promises. 

With a deep sigh, Sans dispelled the bone in his hand and crouched down again, this time right next to the baby. 

“you’re lucky the woman who lives here is such a nice lady,” he told the baby, watching it squirm on the floor. 

The baby whimpered again. 

“where’s the lady anyway?”

More wailing noises. He ignored them and stood up, looking around again. There was a second door right across the first one, leading deeper into the ruins. He was about to walk up to it when he remembered that he had a promise to keep, and he looked back down to the baby. 

He had to protect it. 

His grin became a bit less relaxed and friendly.

A look back to the first door helped him with his decision. He walked back to it, took a closer look at the hinges and the lock of the door. It only opened into one direction, outwards from where he stood. There were no handles, but a small hole on the inside of the door that he could put three phalanges into. He could feel a latch there that he could push and pull from side to side. So the door really could only be opened from the inside. 

With a final look outside to the path leading back to his station, he pulled the door close and slid the latch into place. 

There. 

The door was closed and the only remaining entrance to this room was the one he was going to go through. Good enough for now. 

“stay here,” he told the baby.

It made an unhappy gurgling noise that he chose to interpret as agreement. 

Leaving the room, he found himself in a long, straight corridor, purple stone walls and a stone floor in a gradient from light to dark purple leading down to yet another door. He approached cautiously, found it slightly ajar, and peeked through the gap. 

Behind the door he saw dust on the floor. 

Crap. 

There were scorch marks surrounding the dust and he could see some on the wall, too - it wasn’t hard to imagine out what must have happened here. A human decided to fight, possibly scared and wanting to protect its baby, won but got severely burned in the process, made it through the corridor and to the final door before it collapsed. 

Sans opened the door carefully, confirming that there was nobody else around, before he stared down at the small pile of dust sadly. 

There was no strong evidence that this was the lady, but there had never been anyone else at the door. He couldn’t imagine it being anyone else. 

“ ‘m sorry,” he mumbled. He felt oddly lightheaded.

The dust didn’t reply, not that he expected it to. 

But he already missed that warm, friendly voice that had loved his jokes as much as he himself did, missed his best audience, missed hearing her tell jokes back. 

He allowed himself to take a moment, just to collect himself, before he pushed forwards. 

The room he was in now was small, and had another open corridor leading around a corner a short distance away. He walked up to it and peered around the corner, finding another long corridor with a set of stairs at the end. Should he? 

He thought of the baby back at the door. 

Decided a few more moments wouldn’t hurt.

He approached the staircase and slowly made his way up until he found himself at the top in an open, cozy foyer. It appeared to belong to a house; there was an entrance door between two windows opposite the staircase, and to the left and right open doorways lead to what looked like a hallway and a living room. 

“hello?”

There was only silence. 

Had this been _her_ house? 

Sans took a quick, superficial look at the rooms - the living room and the connected kitchen with a fresh pie still sitting on the counter, tasting like cinnamon and butterscotch; the hallway and the three rooms it lead to; a bedroom, a kid’s room, and a bathroom that was halfway through renovations - before he made his way back down into the cellar through the long corridors leading to the door to the rest of the Underground. 

The baby was where he left it, right next to the burnt corpse of what he assumed to be its parent. It wasn’t whining much anymore. 

“you asleep?”

It was hard to tell, with the way the baby’s eyes were scrunched up. He leaned down and picked the baby up, awkwardly trying to support its neck. He felt he had heard that was a thing you were supposed to do somewhere. Probably. It didn't look like it could support its neck by itself, in any case. The baby huffed and squirmed in his arms, apparently not asleep after all. He decided to put the baby in the crook of his right arm, to leave the left one free for operating doors and magic, should he need it. It hung there like the useless lump of meat it was. 

“you’re kinda flabby,” he told it. 

It occurred to him that the baby might have gotten hurt, either in the fight its parent had or when the adult broke down and died. Probably should have checked that first. He looked the baby over, but couldn’t see any burns, scrapes or bruises on it. Systematically working his way through all the moveable parts, he gently pushed the limbs this way and that, looking for signs of pain. There were none. The baby just kept huffing silently in his arms. 

“i’d say you’re good to go,” he declared. 

The way back to the house was quicker this time around. It was only when he stood in the foyer again that he noticed that he was at a loss as to what he was supposed to do next. 

“uh.” 

The baby squirmed, its face scrunching up. It was quietly starting to wail again.

Sans stared at it, scrambling for a course of action. He had promised the lady to protect humans from the ruins, and he was sure that even though the baby hadn’t come out of the ruins, this still counted. _She_ would be horrified if he left the baby. Would have been horrified. But what in the Underground was he supposed to do with it now? He couldn’t stay and take care of it, but leaving it here all by itself was no option either. Maybe he could drop it off somewhere? He couldn’t think of anyone who would be willing to shelter and raise a human baby. The only monster he could imagine doing something like that was the old lady, and all evidence pointed to _her_ being dead. 

“what am i gonna do with you now?”

The baby started crying. 

He rocked it a bit, not knowing how exactly to go about it. What if he jostled it too hard and hurt it? How fragile were these things anyway? The baby kept wailing and he rocked a bit harder. 

“uh. it’s okay?” He tried. “shush?”

The baby’s wail became louder. 

“ya… ya hungry? ‘s that it? right, food. c’mon, no need to cry, imma make ya… somethin’.”

He had no idea what he even could make. Slowly, he made his way into the kitchen behind the living room. Keeping the baby in the crook of his arm, he took a look inside the fridge and some of the cabinets, ignoring the pie for now. He was reasonably sure that cinnamon-butterscotch pie wasn’t adequate food for babies. 

The fridge was well-stocked with fresh produce and containers of pre-cut vegetables. And snails, for some reason. There were potatoes in one of the cabinets under the worktop and some dried plants he couldn’t identify. He decided to go with the potatoes. Potatoes were always a safe choice, and easy to mash. 

“hang in there, buddy. i got this.” 

The baby didn’t seem reassured by his words, and kept crying. It was beginning to grate him, if he was being honest. He found himself at a loss when he took the knives out and then didn’t have another hand free to actually use them and peel the potatoes. What now? He couldn’t just put the thing on the floor. Even though he had initially left it lying on the floor. It seemed as if that was a little bit not okay though, in retrospect.

“ugh.”

He gently extended his magic towards the baby's soul. Should he? 

It was probably fine. There was no reason to assume this would hurt the baby. 

“don’t freak out, ‘kay? i gotcha.”

With a stronger push of his magic, the soul of the baby turned blue with a high ringing sound, and it took only a quick flick of his fingers to remove the gravitational pull on it entirely. He let go of the baby at about the height of his head and it floated there, unsupported in the air. 

It blinked at him with an almost comically surprised expression on its round, soft face, so much that he had to laugh before he turned to peel the potatoes. 

Then the baby really started to scream. 

“shit,” he said, turning back to it again, to see if something was wrong, but the baby just hung there in the air. Nothing had changed, it just suddenly started to wail loudly. 

“hey, it’s fine, i won’t take long, okay? calm down.”

The baby did not calm down. 

Sans didn’t know what to do with the baby, it was crying before and it was crying now and the only ideas he had to calm it was shushing it or rocking it or feeding it. The first two hadn’t worked and he was now attempting the last one, but for that he needed the baby out of the way so he could peel the potatoes. He was beginning to feel a headache pressing against his skull at the constant loud noise and it aggravated him.

“shut up, for heaven’s sake!” 

The baby only continued to scream. He peeled the potatoes a little bit faster, a little bit sloppier, and set up a pot of water to boil. As soon as the water was hot enough, he added the potatoes. He hesitated over the salt. Mashed potatoes with no spices was bland beyond belief, but was salt healthy for babies? His brother kept nagging him about his own sodium intake and he was a grown skeleton, so he wasn’t sure if babies were supposed to eat spices before a certain age. Fussy little shits. He decided to leave them for now, if the baby didn’t like the bland mashed potatoes he could still salt them. 

That sorted, he finally pulled the baby down from the air, let go of its soul, and cradled it in his arms again, rocking back and forth. 

“shh, it’s fine, see? food’s cooking and you’re not floating anymore.”

The baby didn’t seem impressed by the positive development of events. It kept screaming at full volume. 

“what do you _want_ from me,” he asked the baby, despite knowing that he wasn’t going to get an answer. “i’m doin’ what i can.”

The baby kept screaming the entire time until the potatoes were done. He felt sorely tempted to just call it a day as soon as the potatoes started to soften even slightly, but then even he didn’t like to eat half-raw potatoes, so he didn’t. The baby went up for another brief stint in the air while he drained the water from the pot and mashed the potatoes. Armed with a teaspoon, he attempted to feed the infernally loud creature in his arms. 

“here you little devil. feeding time.”

The baby screamed more. 

“ugh.”

He blew some air on the spoonful of mashed potato in his hand, tested the temperature, and held the spoon against the mouth of the baby. A few hiccuping sobs, and then the screaming subsided. 

Sweet relief. 

The baby closed its toothless mouth (so weird) around the spoon.

“Mmmmmh,” made the baby. 

“finally,” Sans grumbled. His ear canals felt like they were ringing from the earlier assault on them. 

“Ah,” made the baby, opening its mouth again now that it had swallowed the first spoonful of mashed potato. Sans gave it another one, and then another one, until he had slowly shovelled a decent portion of mashed potato from the pot into the baby’s mouth. When the baby didn’t open its mouth for him anymore, he put the spoon into the pot and just left the entire thing on the stove. He didn’t feel like taking care of that right now. 

The baby was back to emitting small huffing sounds. 

“think i can leave ya alone for a bit?” He asked the floppy little creature in his arms. 

The baby yawned. 

“yeah, sounds good.” 

Sans made his way back through the living room and the hallway, and from there to the bedroom with the large, queen-sized bed. He was about to just plop the baby on the bed and be done with it, but then he eyed the edge and wondered it the baby wouldn’t fall if he did that. Why did everything have to be so complicated? He tugged the cover down from the bed and spread it on the floor, surrounded the centre of it with several pillows, and then placed the baby in the middle of that little nest. That looked good. Comfy and not dangerous, so it was good enough for a baby, right? 

The baby seemed to agree, yawning again. 

Sans took the opportunity and took a closer look at the bedroom. The queen sized bed, a desk with a chair, a book shelf, an armoire, some plants, the furniture in soft shades of pale blue. He carefully approached the desk, eyeing the open book lying on its surface. It looked like a diary which made him hesitate, but the format on the penultimate page looked familiar from his own joke book, so he ended up reading that bit anyway. 

“why did the skeleton want a friend? because he was bonely.”

The silence in the room, only interrupted by the faint breathing of the baby, suddenly felt oppressive.

“heh. good one.”

Sans felt oddly heavy and light headed at the same time. 

It was a good joke. Right up his alley. 

_She was dead._

His eye lights sputtered out, leaving his vision dark and fuzzy. 

_A pile of dust. She would never make jokes again._

Sans took a deep breath and despite his initial reservations looked at earlier pages, skimming the rest of the diary. Most were covered in descriptions of everyday life. Errants, conversations with monsters, little observations about the ruins. The diary dated back a year or so and he found the entry the lady must have made after meeting him. 

‘There is a voice on the other side on the door. They tell knock knock jokes. I could not help myself and laughed. This voice… for some reason, I felt drawn to it. I must be getting lonely. I have told them a joke too. Tomorrow I will return.’

He flipped the pages. Descriptions of meetings and conversations and jokes. A new joke every day.

‘My friend at the door is very good. He has a show at a hotel I have never heard of. I missed so much since I left New Home… speaking to my friend, I am learning much of what I missed, even though this is not the reason for our conversations.’

More pages. More jokes, more conversations, deepening in seriousness and honesty. The development of their friendship. 

‘I have asked him. I was not sure if I could, but this person has a humour and patience that is impossible to distrust. He made the promise to protect any humans that may come from the ruins. Even though there is no human here at the moment and I do not intend to let them leave if another one should fall, with this promise I can rest a little easier.’

Sans sighed. He still wasn't sure if making that promise wouldn't bite him in the tailbone somewhere down the timeline, but reading this he couldn't blame himself for making it anymore. 

He skipped another couple of pages, skimming descriptions of his friendship with the lady behind the door, wistful with the knowledge that _she_ was gone and this was all he had left of _her_ now. 

The last pages after finally contained the entries about the human and the baby.

‘A human has fallen and with them, a very young child. Only a baby. I met them fighting that miserable creature, who was trying to hurt them. Despite my attempts to help, they defeated the evil creature. The human would not trust me afterwards, and attacked me. I returned home to recuperate, but I shall try to strike out to the ruins once more to speak with them.’

‘My efforts were futile. The human was still in the cave where I left them, but upon seeing me they began screaming and initiated another fight. They do not seem to feel safe in my presence at all. I have returned home to make a pie as a peace offering. Surely if I try hard enough, I can prove my good intentions and show the human that there is nothing to fear, and that staying with me would be in their best interest, for the baby as well.’

‘I noticed I was out of cinnamon, and left to obtain more. On my trip through the ruins, I encountered piles of dust… it appears the human has not been peaceful after all. Was it my fault for not having tried harder to convince them of the goodness of monsters? I mourn for my friends. I have returned home and intend to stop them, before they pass through the door to the rest of the Underground. They cannot be allowed to hurt any other monsters.”

That was the final entry.

Just as he thought then. He turned around to watch the baby on its blanket on the floor and finds it fast asleep. So much trouble. So many monsters had already died in the name if this tiny little thing. 

And now he had to prevent it from dying in turn. 

What a _joke_. 

Sans couldn't find the humour in the situation no matter how hard he tried, but he knew that he would try to keep his promise no matter what. He couldn't stop honouring it when his friend had ultimately died trying to protect him and the rest of the Underground. 

With the baby now asleep though, he felt that it was safe for him to continue his investigations. He checked that the small creature was indeed not awake and that the pillows surrounding it would make sure that it wouldn't roll off in its sleep. He had no idea if that was a thing that could happen, so he felt it was better to be safe than sorry. 

After that, he left the small house through the front door and began his exploration of the ruins. Past the tree in the courtyard in front of the house, a path leading to a viewing platform allowed him to look over the ruins and try to see some of what awaited him. After taking a good long look, he went down the other path and made his way into the ruins. On foot, without any shortcuts. He carefully inspected each room and corridor he found himself in and just like the lady had written, there were piles of dust everywhere, in the corners and on the path and mixed with the orange leaves and in side rooms and cellars.

His hopes of finding survivors against all odds (his hopes that _she_ had survived despite all the evidence against it) diminished with each new pile he discovered. It was a massacre that left him feeling sick and disturbed. At one point, he found himself in a darkened room similar to the one directly behind the entrance to the ruins, where he found the baby. In the centre of the room, illuminated by a very faint shaft of what he assumed to be sunlight, there was a single golden flower. Its petals were slashed and torn, its stem bent and sap had seeped from the many gashes in it and bled into the ground. 

Sans didn’t know why, but the sight was somehow worse than the piles of dust he found on the way here. The flower unsettled him and he hesitated in his approach, only daring to step closer when he had a blaster ready to fire next to him and a bone ready to wield in his hand.

His caution turned out to be unnecessary.

The flower did not stir as he approached and even when he dared to prod it with his bone, it just slumped over further, the broken stem no longer able to support its weight. 

He crouched down next to it to take a closer look, wondering why this small plant had such an emotional effect on him. It wasn't anything special. Just a golden flower, similar to the ones growing in some places at the dump or in the throne room. A round centre with six evenly spaced petals surrounding it, the petals slightly darker in colour than the centre. A green stem without leaves. 

And yet. 

Why would someone even feel the need to slash a flower? Trampling it would be the most logical action if one didn't like flowers - unless there was a reason to take more drastic measures. Considering what the lady wrote in _her_ diary, he suspected that this was the ‘miserable creature’ the human had been fighting before the lady tried to intervene, even though he had never heard of a monster looking like a golden flower before. No, it couldn't be a monster, actually. Or else it would have turned to dust. What was it? Prodding it some more did not yield any answers.

Sans rose from his crouch and left the strange flower behind, turning to explore the rest of the ruins. He didn't find much more, a single corridor ending in a room with a rectangular patch of more golden flowers in the middle, the room illuminated by light streaming down from above, slightly less faint that what he had seen so far. This must be where the humans had fallen. He allowed himself a moment to crane his neck back and squint up at the light, and the hole it fell through. The light appeared faintly distorted - he was fairly sure he saw a flicker that must be the barrier - but it was still somehow warmer and more pleasant than the magical light illuminating the Underground. This room was more peaceful for it, despite the human murderer who had landed here. 

The human murderer who still lay all burned behind the door of the ruins. 

It galled him, but the idea of leaving that corpse lying around somewhere felt wrong to him. 

He could no longer stall. 

If he wanted to keep his promise to the lady, that meant that he couldn't let anyone else into the ruins. He would have to be the one taking care of the place for now.

Sans would have to bury the human, and then think about what to do with the dust of all the monsters that had died here. And the flower. Despite the thing giving him the creeps, he didn't want to leave the flower out in the open with its gashes and broken stem. That felt wrong, too. 

With a sigh, he pushed himself through a shortcut, back to the body of the human murderer. It smelled awful by now. He didn't really need to touch it to take it with him through a shortcut, which was a relief because standing in the vicinity of the corpse was enough to make his bones rattle. He brought the corpse back to the flower patch with another shortcut, and then went back to the house to look for a spade. 

He began digging next to the flowers and angled his descend sideways so the human would rest underneath the flowers. Humans didn't turn to dust, instead leaving behind all of this gross biological stuff, so they couldn't really join their last remains with a meaningful object like monsters. But if he buried the body under the flowers, it would decompose and the flowers would gain nutrients from it, and that was at least coming close. It was also less wasteful than just rotting in the earth without purpose. 

Digging a hole big enough for an adult human body turned out to be more work than Sans expected. He wanted to take breaks, or at least switch to taking care of the dust, but he had a feeling that if he stopped, he wouldn't be able to start up again, so he kept at it in spite of himself.

When the hole was finally long and wide and deep enough, sweat had collected on his brow bone and his phalanges, metacarpals and carpals hurt from the exertion. For a second he hesitated, not wanting to touch the corpse, but then he pulled a handkerchief out of his pocket and began to push. He'd just… bury the handkerchief with the human or something. He wouldn't want to use it anymore. The corpse did not slide into the ground easily or quickly. And after that he was still not finished, having to shovel the mounds of earth back into the hole to cover it. When it was finally over, he felt even more frustrated with how cumbersome humans were when they died.

He didn't like them. 

At least this one was buried now, gone and no longer his problem. No longer his responsibility. He hated that it had been his responsibility in the first place. And that there was more waiting. 

Sans turned his back to the flower patch and started to walk back to the ruins. He stopped in the room with the single broken flower. It still gave him a bad feeling, he wasn't sure about leaving it here. He picked it up, a few shrivelled roots leaving the earth easily, and returned to the flower patch, joining the destroyed flower to all the healthy ones. A double grave for a human and a miserable creature. Murderer and murderer? Who knew. Sans didn't, but it felt right. 

Now, the dust. He didn't know who all the monsters had been who had died here, and he didn't know what their most favoured possessions and locations had been. But he couldn't in good conscience leave their dust to sink into the ground like that, to be bound to the place where they had been murdered. The flower patch was out too, burying them together with their killer would have been a perverted action. 

In the end, he spread their dust on the roots of the tree in front of the lady’s house. It was a peaceful and pretty place, good for the final rest of those who had been brutally torn from life. He needed a dustpan and many, many trips before he was sure he had found every little heap of dust there was, since there were so many, and some were hidden from sight by alcoves or leaves or the dust was in holes and cellars. He was very thorough in his search, looking in every nook and cranny again even after already feeling sure that he must have found everything. 

And then he couldn't stall anymore. 

He didn't want to do this. 

But he had to.

He took a shortcut into the house, but he walked down the stairs on his own feet. 

Passed through the corridor, turned the corner. 

And came to a stop in front of the door at the end of it, where one last pile of dust lay.

He kneeled and scooped it up with the dustpan, more carefully than he had any other. He made sure he got every last grain. Another shortcut brought him back into _her_ room, where the baby was still lying, awake by now but not screaming. He paid it no mind as he approached the desk.

When the dust hit the diary he poured a little of his magic with it, to make sure it would take. The dust vanished into the page with the last joke on it, about a skeleton being bonely, and left nothing behind but a fine sheen on the paper. 

Sans stared at it and reached out with his hand, traced his fingers over the word, ‘bonely’, and closed the diary. He picked it up and put it in his pocket.

He didn't think about anything but that book when he took a shortcut straight to his own room and fell asleep.


	2. Baby Blues

“SANS? ARE YOU STILL ASLEEP? WAKE UP, YOU LAZYBONES!”

Sans felt as if he was dragged into awareness through something thick and sticky, like honey perhaps. 

“SANS?!” 

“ ‘m up,” he mumbled, voice still deep and rough from being sleepy. His brother heard him, as he always did in spite of his own volume. Papyrus knew his brother was quiet, and paid extra attention to overcome their differences. He was just cool like that. Not like Sans, who could never be bothered to make an effort. 

Or at least he made only the barest amount of effort, sometimes, on a good day, while his brother always and without fail went the extra mile. 

With a sigh, he heaved himself out of bed, looking around for his hoodie jacket. Did he need to change? He couldn't spot any stains on his shirt or shorts, so probably not. He picked up his jacket, ignoring how full the pockets were like he did every morning, and made his way out of his room and down to the table where his brother had already served the breakfast spaghetti. Today's batch looked softer than usual, kind of mushy. Something about that almost made him stop in his tracks, but he couldn't figure it out yet. Too sleepy. He needed food first.

“looks great, pap,” he said while meaning it, it looked a lot better than yesterday's half-raw batch at the very least. Mushy at least was edible. 

There it was again, that prickle at the back of his mind, like he was forgetting something. 

He ignored it. 

He didn't really like that feeling, never liked it, it set his teeth on edge. 

“OF COURSE! YESTERDAY'S TRAINING WITH UNDYNE TAUGHT ME SEVERAL NEW METHODS OF PREPARATION THAT I IMMEDIATELY EMPLOYED! SOON I WILL BE THE MASTER SPAGHETTORE THAT I ALWAYS WANTED TO BE!” Papyrus struck a dramatic pose with his hand on the chest plate of his costume, his scarf fluttering in a nonexistent wind behind him. He looked very cool. 

“tastes good too,” Sans mumbled past a mouthful of spaghetti, ignoring that the whole affair was so soft that he needn't have chewed it at all. He could just take a bite and swallow if he wanted to, like a -

His fork clattered against his plate at the same time his eye lights winked out. 

Oh no. 

“SANS?” 

He forgot. 

“SANS?!”

He _forgot the baby_.

“i gotta go.”

“WHAT? WHY? YOU NEVER SKIP BREAKFAST! HAS THE QUALITY OF MY NEW RECIPE OVERWHELMED YOU?”

The anxious worry on Papyrus’ face, contrasting sharply with his overconfident words, brought Sans back into the present. Papyrus needed reassurance like other monsters needed magic to live, and Sans would never deny it to him. 

“no, i forgot to do something at the sentry station yesterday, heh.” It was an excuse that would buy him some time and earn his brother's approval. “think i’d better go and check… “

“OH! YES, OF COURSE, I'M GLAD THAT YOU'RE TAKING YOUR WORK SERIOUSLY FOR ONCE!” Papyrus gave him a proud smile and Sans felt a little guilty for lying to his brother. “YOU CAN ALWAYS FINISH YOUR BREAKFAST SPAGHETTI LATER!”

“actually…” Sans looked down at his plate full of mushy noodles with a thoughtful expression. “mind if i take it along?”

“AS LONG AS YOU DON'T BREAK THE PLATE AGAIN!”

“i won't. see ya later, pap.” 

Sans grabbed the plate and fork, and took both into the shortcut with him. 

He emerged into a cacophony of angry screams. 

“shit.” 

He put the plate aside on _her_ desk and crouched down in front of the baby. It smelled really bad by now. Probably needed a shower? It smelled fine yesterday though. Did humans really get dirty that quickly? Sans and his brother didn’t need showers that often, unless they had done hard work or fell into dirt or something. The baby had just been laying here. Humans were weird. Regardless, he had to do something.

“sorry. sorry for forgetting you, ‘kay? c’mere, i got food for ya - “

Sans brought his hands under to baby and paused. It's bottom part felt oddly soft and squishy, more than normal, and wet - 

Stars, no. 

Please. 

He quickly pulled back his hands, which only made the baby scream even harder. What should he do? He didn't want to touch… that. But he couldn’t leave the baby this way. Once more he felt deep regret for making that promise, followed by guilt because he knew how important it had been to _her_. He swallowed his feelings and began to fiddle with the onesie. How did these things open anyway? It took him a few moments to find the little buttons on the baby's shoulders, the piercing cries of the baby ringing in his ear holes the entire time. What an inconvenient way to sew a garment. Taking it off was way more complicated than necessary. Especially with how the baby was struggling.

As soon as he peeled the cloth away from the baby, it became apparent why it was so unhappy. Underneath the onesie, it was wearing a strangely plastic-like sort of underwear that wrapped tightly around the bottom half of the human's torso and appeared to be cushioned on the inside with soft cotton. The cotton was soaked beyond capacity and both liquid and other waste leaked out at the holes where the legs emerged. 

Sans felt a curious sensation at the back of his mouth that seemed closely related to his disgust. He imagined this must be what humans feel when they felt sick, and briefly almost regretted not being capable of that experience. It was unreasonable of course. If he could, he'd have twice the mess to clean up. 

He looked for a way to remove the padded underwear and briefly marvelled at the idea. It made complete sense that a human incapable of taking care of itself or walking would need something to catch any... waste, and padded underwear was a simple and yet efficient solution. He just regretted that he was the one having to take care of it now. How long did humans remain in this helpless state anyway? He didn't want to do this once, let alone repeatedly. 

He was stalling. 

His phalanges carefully opened the fasteners at the front and the padded underwear fell open, revealing the mess within. Stars, this was bad. The stench was as unbearable as the sight and Sans felt tears sting in his eye sockets. He didn't want to touch it. But taking it through a shortcut without touching it could mean that the mess would land on - or worse, _in_ \- somebody, so he had to. 

First though, he needed a replacement, and something to clean the baby with. 

Thinking for a moment, he simply gripped the baby under its arms and blipped into the bathroom that was only half finished. The shower wasn't functional, but the sink looked done. He sat the still screaming baby into the sink, ignoring how the pitch of its screaming increased at the contact with the cold surface, and turned on the water. It worked, but the water was still cold. Despite the truly infernal screams, Sans managed to persist until the water temperature increased to something more comfortable. He just let the water flow over the bottom of the screaming baby for a while, until most of the mess was gone. Despite the warm water, the baby was shivering. It had screamed itself hoarse by now and Sans would almost feel sorry for it, if his head didn’t hurt so much from all the noise. 

Sans left it in the sink for a moment while he looked around for towels. He found them in a cupboard in the corner and brought back two: one he used to dry the baby, the other he bound around the bottom of the baby to replace the padded underwear it had been wearing. Looked a bit shoddy, but it would do. Probably. It was better than nothing in any case.

He dearly wished he could stay in this bathroom, where everything smelled nice and clean, but he didn’t actually have that much time. His brother would come to his sentry station soon. 

With a sigh, he took a shortcut back into _her_ room. The smell of the baby’s waste overpowered the faint scent of fur that lingered here as well as the smell of his brother’s spaghetti. The sight of it caused his throat to itch again. He put the baby down on the blanket pile, far enough away from the soiled padded underwear that it wouldn’t dirty itself with how it was squirming. He didn’t want to, but with two phalanges, he took the very outermost tip of the thing and held it. It didn’t look like it could be reused, which was a shame, but that also made everything easier. He quickly blipped over to the dump, dropped the thing, and immediately returned to _her_ room. 

There. 

Much better. Some of the stench still remained, but if he washed the onesie and left the door open for a bit, it would soon be gone. He got started on the first part right away. Sans took the onesie and looked it over. There were wet and browned patches at the bottom and on the legs; some of the waste must have leaked through the leg holes of the padded underwear. He couldn’t make the baby wear this again until it was clean.

He took the onesie over to the bathroom, holding it under running water and the leaving it in the sink to soak. On his way back, he went back into _her_ room on foot, leaving the door open.

The baby was still screaming, but it wasn’t quite as loud anymore. Closer to crying now. Still hoarse though, and still shivering. Right, clothes. He sighed, and decided to look for something fitting in the neighboring kid’s room. After a quick shortcut, he found that the cupboard held mostly clothes for older children. He picked the smallest shirt he could find and popped back into the other room. 

There, he carefully wrangled the baby's head and arms through the appropriate holes. The shirt was far too big for the little thing, with the sleeves reaching down and covering most of its hands and the neck hole flapping about. The shirt was long enough to cover its feet like a dress.

But hey, at least it was covered. Hopefully it would stop shivering soon. 

Sans eyed the spaghetti, but then he remembered that his brother wanted to check on him at his station. 

How long had he been here? It had taken some time to bathe the baby, take care of the waste and the onesie, and then clothe the little thing… 

“damn,” Sans murmured, popping over to his sentry station and leaving the baby where it was for now. He didn't like it, but he didn't know what else to do. 

His station stood in silence, with no new tracks leading up to it yet. Good. Perhaps then he could - 

The crunch of snow around the corner told Sans that he appeared just in time. He heavily sat down in his chair before his brother came around along the path, spotting him immediately. 

“BROTHER! YOU ARE INDEED AT YOUR STATION,” Papyrus exclaimed happily. “FORGIVE ME FOR THINKING YOU WERE MAKING UP AN EXCUSE TO LAZE AROUND AGAIN? I WAS COMPLETELY WRONG ABOUT YOU FOR ONCE!” 

Papyrus looked so proud of him that Sans felt crushed under his guilt. Keeping stuff from his brother wasn't anything new, but this was the first time where the secret keeping wasn't for Papyrus’ own sake. 

It was just that Papyrus wanted to capture a human so badly… and Sans couldn't allow that right now. He had a promise to keep. 

“don't worry about it. we both know you'd normally be right,” he assured his brother calmly. 

“INDEED! BUT THIS IS A CASE WHERE THE GREAT PAPYRUS IS GLADLY WRONG! SO, DID YOU DO IT?”

“uh… what?”

“THE THING! THAT YOU SAID YOU FORGOT!” Papyrus gave him a questioning look. 

“oh, uh, right. turns out i already did it yesterday after all, heh.” Sweat began to form on Sans’ skull. Damn. The baby had screamed so much that his head felt fuzzy. He was distracted and not at his best. He had to get back on top of his game. 

“SO WHAT WAS IT?” His brother wanted to know. 

Shit. 

“uh, my ketchup bottle was empty,” Sans said quickly. Only to look down under the counter of his station and see his ketchup bottle… empty. Crap. When he looked up, he could see his brother looking at the counter of the sentry station, following Sans’ eye lights. Papyrus caught his gaze when he looked up again, making Sans even more sweaty. If Papyrus asked to see the bottle now...

“SANS… ARE YOU ALRIGHT?” Papyrus asked instead, wringing his gloved hands. His expression was now a worried frown. “YOU SEEM OUT OF IT.”

“same as always then?” He tried to joke, but that only deepened his brother's frown. 

“WHERE ARE THE BREAKFAST SPAGHETTI?” Papyrus asked. 

Crap. 

“i already ate them. they were good,” he quickly assured his brother. Who, for some reason, didn't seem as assured as he should. 

“WHERE IS THE PLATE?” He asked, narrowing his eye sockets at Sans. 

In the ruins. Still full of spaghetti waiting to be mashed and shoveled into the mouth of a hungry, screaming baby.

“i, uh, kinda misplaced it,” he fumbled. “not broken though. don't worry. i'll find it eventually.” 

Papyrus’ expression twisted further into worried and Sans noticed belatedly that he hadn't made a single pun yet. Not one.

“SANS,” his brother said as stern as he could. 

“can't hide anything from you, huh?” Sans sighed. He went for the easiest and most believable lie. Trying to get back on top of it. “didn't sleep well, to be honest. don't worry about it, i’ll just take a nap later and i’ll be fine.”

He winked at his brother. This wasn't a _complete_ lie at least. With the stress caused by the baby and the heavy memories of dust and… _her_ , Sans didn't feel all that well rested. 

“ARE YOU SURE?”

“yeah, bro. you know me. i just get bone tired sometimes, heh.” 

It was a weak effort even for him, and Sans knew it. But Papyrus had the good grace to play along and stomped his foot against the tightly packed snow that covered the path. 

“SANS, STOP IT WITH YOUR INFERNAL BONE PUNS ALREADY!”

“sorry bro. to patella the truth, i’ve been thinking i should make up some new ones myself.”

“I WOULD RATHER SEE YOU PUT SOME BACKBONE INTO YOUR WORK FOR ONCE!” Papyrus insisted and grinned at his brother, proud at his bone pun in spite of all his loud derision of them. Sans felt his skull fall into an easier, more genuine smile. Something familiar and warm that only Papyrus ever truly managed to bring out.

“good one, pap.” Praising his brother was easy. No matter how tired Sans felt, it was still easy. The whole interaction soothed his soul and calmed his nerves from the sudden stress of the morning. 

“BUT OF COURSE! NYEH HEH HEH!” Papyrus threw him a salute and quickly ran back down the path to reach his own sentry station, the one that Sans helped him built so his brother could feel like he was truly a part of the guard even when… well. When he wasn't yet. Papyrus stopped just before the corner. “HEH!”

Sans chuckled to himself when his brother turned around the corner and left. He allowed himself to bask in the familiar warmth of brotherly affection for just a moment, before his smile fell. 

Sure would be nice if he could stay here and go along with the flow. Fall into his routine and do what he did every day. But there was a baby lying in an oversized shirt on a floor waiting for him to feed it, and he had made a promise. 

Couldn't _she_ have asked him something else?

With a deep and weary sigh, Sans stepped through another shortcut back into _her_ room. The baby was where he left it, squirming and hiccuping, its face stained and crusted with the salty residue of their tears. He'd feel sorry for it, if the racket it made hadn't cause him such an ache in his skull that he made his brother worry. 

Still. 

“c’mere, you useless lump,” he mumbled, wiping the worst of it away with a corner of his shirt. The baby whined at that, its voice cracking and rough. 

“you don't sound so good,” Sans noted, shuffling over to the desk to fetch the plate of spaghetti. He began mashing the soggy noodles with the fork he had brought along, pleased that his prediction had been correct. They were easy to turn into something that he could feed to the baby, the yellow of the noodles and the red of the tomato sauce mixing into a reddish brown slurry. Good enough. More than good enough for the little brat. 

He glanced at the fork in his hand. That was probably not good feeding equipment for squirmy little babies who were dumb enough to stab themselves on something as harmless as a fork. 

With a sigh, he left the room once more to fetch a spoon from the kitchen. The pot of leftover mashed potatoes he made yesterday still sat on the stove, unused and cold by now. He’d have to put that into a container at some point; even if monster food didn’t spoil it could get dirty and attract germs or vermin, and so it was a good idea to keep it safely contained. 

He could do that later, though. 

Right now, he had to focus on finding a spoon, feeding the baby, and then returning to his station just in case his brother decided to come by again, which he did often throughout the day, to check whether Sans was doing his job and not slacking off again. And to bring by some extra spaghetti or even a whole lunch packet. That was always nice, even though Sans preferred to have his lunch at Grillby’s. A couple of fries or a nice burger, washed down with ketchup… Grillby simply had the best ketchup in the Underground, better than the cheaper stuff Sans would buy for himself. 

Sans paused in his ruminations about his usual routine, noticing something he had forgotten until now. Thinking about ketchup reminded him that the baby hadn’t had anything to drink yet, had it? No wonder it sounded so bad. What did babies even drink? Milk? Juice? Tea? He wasn’t sure. He didn’t have any of those on hand though; there hadn’t been any when he checked the refrigerator and cupboards yesterday. Water would have to do then. 

He drew a cup of water from the tap and then, armed with a small spoon and the filled glass, he returned to the baby and settled down next to it. The baby was still whining, its voice painfully dry. 

Sans eyed the glass of water in his hand. He wouldn't be able to give this to the baby while it was lying down, so he'd have to pick it up. Even though he really didn't want to hold the thing more than strictly necessary. 

He promised. 

With a low grumble, he put down the water and spoon, picked up the baby and awkwardly settled it into the crook of his right arm. When he brought the glass to the baby's lips though, it didn't get what it was supposed to do and much of the liquid seeped down its body and into the towel wrapped around it. Sans groaned and hung his head. Of course it didn't know how to drink. Of _course_. 

The baby kept whining with that pained, rough voice. He couldn't stop now. The second try didn't go much better, and neither did the third. In the end, he opted to spoon the liquid into its mouth bit by bit. It was still whining, but at least he was getting some liquid into it.

It was a slow process, but after getting a decent amount of water into the baby, it sounded a lot better. It still looked unhappy, but Sans couldn't stay here forever. He carefully put the baby down and the eating utensils and glass out of reach, before taking a shortcut back to his station. 

There were no new tracks in the snow, so his brother mustn't have come by yet. That was good, since it meant Papyrus hadn't noticed his absence. But it also meant that he could arrive at any second - or much later. How was Sans supposed to wait here, knowing that he still hadn't fed the baby? And how was he supposed to leave, when that might alert his brother?

He had taken care of the baby for less than twenty four hours and he was already exhausted. It was more effort than he had expended on anything in years and he didn't want to do it anymore. 

He touched the book with _her_ dust on it that he still carried in his hoodie pocket. That helped a little. But only a little.

To go, or not to go. 

He decided to risk it. He could always claim that he heard something in the forest and went to inspect it, if his brother asked. More lies, and more guilt, but it would probably work.

Another shortcut back to the ruins. Sans felt thankful that his magical reserves ran so deep, because this was a lot of exertion for his powers in a very short time. He didn't feel tired yet, but he wasn't at full energy anymore either. He'd need to eat more if he kept this up, to replenish his stores.

He sat down heavily next to the still fussy baby with a sigh, and took the spoon in hand. He brought the food into its mouth almost mechanically, barely taking care to make sure nothing too much spilled. Despite that, the baby ended up with mashed spaghetti smeared everywhere on its chin and cheeks. He would have to clean it again. Sullenly, he ate some of the mushy spaghetti himself. It was unappetising, but that was par the course for Papyrus’ food anyway, so he could deal. The baby seemed full now, so he got up and shuffled over to the bathroom, no shortcut this time, and fetched a wet washcloth to clean the baby with. 

It looked up at him drowsily while he wiped the mess off its face. Probably exhausted itself from all the screaming, and now with a full belly, it seemed ready to fall asleep. 

Thank Asgore, that would make things a bit easier. 

He took a brief detour to his station. Still no sign of his brother, and no signs of him having been here while he was away. Good. Back to the ruins. 

He was definitely pushing his luck now. But it was worth the risk of Papyrus finding his station empty in order to make sure the baby was actually sleeping - which it was - and to put the leftover spaghetti and mashed potatoes away. It meant he wouldn't have to cook or otherwise prepare food again later in the day, because he was pretty sure the baby would need to be fed again over the course of the day. The morning had barely passed yet, it wasn't even noon. 

Usually, he'd be thinking about heading over to Grillby’s for brunch soon. 

Sans sighed as he stored the last of the food in proper containers and put it into the fridge. He couldn't think about that now. He needed to know more about babies, desperately, because this one morning had been enough to show him that he had no idea what he was doing. It had been hell, and constantly trying to figure things out by himself while trying to keep his stress levels in check because the baby was screaming had proven to be a less than ideal solution. 

Perhaps _she_ had known something.

He wandered over into the living room and eyed the bookshelf speculatively. There did seem to be several books on humans. He could take some of those and read them at his station; if he hid them in the usual car magazines nobody would notice. The baby was asleep now so he would probably be good for a couple of hours, and then he could return the books he took when he came back to feed the blasted creature again. If he skimmed the texts he would be able to see quickly if they contained the information he needed, and then he could only read those sections in depth that pertained to his situation. Like this he should be able to get through a lot of books quickly.

Plan made, he pulled out several books that looked to be most promising and took a shortcut back to his station. 

Where his brother waited for him, hands on his hip bones. 

Uh oh. 

He needed an explanation and he needed it fast, especially since he couldn't hide the books anymore now that his brother had seen the stack. Damn it. He should have taken less and put them into his pockets.

“SANS! WHERE HAVE YOU BEEN? I KEEP TELLING YOU YOU SHOULDN'T ABANDON YOUR STATION!”

“sorry, bro, i, uh…” Sans shifted, and carefully put the books down on the counter of his station. “i just went to fetch some new reading material. on humans. figured since we're supposed to watch for them it'd be a good idea to learn more about them.”

Papyrus squinted at him.

Sans sweated.

“SANS! THAT IS A BRILLIANT IDEA! YOU ARE WORKING EVEN HARDER THAN I THOUGHT YOU WERE!” Papyrus exclaimed suddenly, and swept Sans up into a hug. Relief and more guilt made their way into Sans’ soul while he hugged his brother back. All those lies. But Sans had no choice. 

“eh, i’m giving stuff a try,” Sans said, patting his brother's back. That wasn't completely wrong at least. He was trying. For that stupid baby. 

Papyrus let go, showing him a beaming grin.

“I THINK IN MY BREAK, I'LL GO TO THE LIBRARBY AND LOOKS FOR SOME BOOKS ABOUT HUMANS TOO! WOWIE! I DIDN'T THINK YOU'D SET AN EXAMPLE FOR ME AS A SENTRY ONE DAY!”

“nah. got that idea from you ‘n undyne. you’re still way cooler than me,” Sans insisted. 

“NYEH HEH HEH. OF COURSE! BUT! YOU ARE STILL DOING VERY WELL TODAY! WELL. YOU MISPLACED THAT PLATE. BUT! IM SURE YOU CAN FIND IT! HAVE YOU FOUND IT YET?”

“yeah. stuck in a snow poff. brought it right back home,” Sans claimed, another quick and easy lie. 

“WELL DONE, BROTHER! I SEE I WAS RIGHT TO BELIEVE IN YOU! I'M GOING TO RETURN TO MY POST THEN!” Papyrus gave him one more look filled with pride and turned on his heel, walking back to his own sentry station with a series of quiet laughs. 

Sans sighed deeply at having managed another sudden confrontation with his brother. Right. That stupid plate. He risked expending more energy on another shortcut to fetch it from the kitchen in _her_ house where he had left it. While he was there, he checked on the baby again, but it was asleep in the nest of blankets and pillows where he had left it. Another shortcut brought him into his own home, where he left the plate in the kitchen sink before he returned to his station. 

He fell into his chair with a tired huff. Truth to be told, he didn't feel like reading at all. He was tired, from the exertion of the constant shortcuts, the screaming of the baby, the stress of the whole situation. Under usual circumstances he'd take a nice long nap now. But he needed the knowledge. He needed to know what to do, how to handle this, so instead of doing what his tired bones begged him to do, he grabbed the first book and started flipping through it and scanning the pages. 

He would keep this promise to his dead friend. He'd learn all about humans and keep this blasted baby safe. He'd figure out how to time things better so nobody got suspicious when he vanished to take care of the thing and he'd make the woman he'd never seen proud. With one hand flipping through the books in front of him, and the other occasionally touching _her_ journal in the pocket of his hoodie, he didn't have a hand free to wipe his face. But that didn't matter. 

Sans didn't notice the tears building up in the corner of his eye sockets anyway.


	3. No Rest for the Skeleton

Sans had a new routine, and it was exhausting him. 

He would start by getting up early, before his brother even woke up. For the first time in many years, he used the alarm function on his cellphone in order to get a start on the day in time. It cost him more energy than he cared to admit to not just hit the off button and turn around to sleep more. Heaving his body off his mattress and into his clothes felt like deadlifting one of the tall pines of Snowdin forest, and it didn’t get any easier the more he got into the habit. He just felt more and more tired. 

As soon as he was dressed, he would take a shortcut into the ruins. Arriving so early, he would often get lucky and find the baby just waking up, although he was just as often greeted by screams. The baby needed to be cleaned every single morning without fail, the padded underwear he created for it always soiled. After thinking about it for a couple of days, he had taken the sewing kit he had used to create Papyrus’ battle body and created several sets of underwear for the annoying creature: he had cut up several of the softest towels he had been able to find in _her_ bathroom, mentally apologising, and sewn them into little underpants made of thick and fuzzy fabric. They could soak up much of the mess that the baby kept making and were easily washable afterwards. While the sewing had taken some work, he could now just quickly slip these on and off instead of having to think about a towel wrap technique that wouldn’t get loose as the baby moved in its nest of blankets and pillows on the floor, so it ultimately ended up saving him time. 

The fact that it still soiled itself was an inconvenience by itself. 

Sans had hoped he would be able to solve this problem fast, since monster food didn’t come out at the other end. But unfortunately, it wasn’t meant to be. He did end up finding some mentions of human babies and their dietary requirements in a single book. 

And most of it had been completely useless.

The most useful had been the handwritten note on a sheet of paper that had been tucked between the pages of one book, stating that humans couldn’t live on monster food alone for a prolonged amount of time. Monster food lacked several of the important nutrients that humans needed, and so eventually they would waste away if they didn’t get those nutrients from other sources. _She_ had also included a recipe for snail pie that used the regular snails common throughout the underground, since these contained many vitamins and other important nutrients that humans needed, apparently.

It was a note written by _her_ and he was grateful for the information and the recipe, so he didn’t want to think badly of it, but… _she_ sure could have included which nutrients those were exactly, so he could figure out more recipes by himself. And _she_ didn’t. 

So he tried finding the information in the book itself, but that was were the next problem occurred. All the notes _she had_ left on human nutrition was meant for older children, not babies. And the requirements for human food were apparently different depending on the age of the human. And unfortunately, the section on nutrition for babies was the least helpful passage of them all, period. 

Babies, so the book stated, needed to be nursed by their mother. The milk that human women produced in their breasts was optimal for the development of human infants, contained everything a human baby needed in the perfect composition, and no substitute would ever be able to compare. Premade formula could be fed if necessary, but breast milk was ideal and up to a certain age either breast milk or formula should make up the majority of a baby's diet. Solid foods in the form of mashed vegetables and other easily digestible foods should only be introduced slowly and later in the development. The book made reference of yet another book that supposedly talked in more detail about that process, but of course that other book was nowhere to be found. And nothing was said about alternatives for when neither breast milk nor formula was available. 

Useless. 

Sans obviously had no access to breast milk, and finding formula in the underground… he had taken a trip to the garbage dump, but it hadn’t provided him with anything close to that. He had, however, found several cans of vegetables that hadn’t rusted yet and seemed intact, so he had pocketed those in order to cook them together with the monster food and feed them to the baby. Hopefully, the nutrients in them would at least be somewhat adequate to keep it alive even without human breast milk.

He really had to wonder why the book didn’t mention any other alternatives. Did human babies never lose their mothers on the surface? Not to wars, famines, or other tragedies? Had humans gotten that peaceful and wealthy? Not if the history books that fell into the Underground were true, that much was sure. But then what did humans do when a baby lost its mother? Did they give it to another woman to feed? What if that woman had no milk? Could humans produce milk by choice, even on short notice? How did breasts even make milk in the first place? And what if no women were available at all, period? Would the people caring for a baby then automatically have access to this formula stuff? And what was that even made of? Could he recreate it? But with what? And if he couldn’t, could he use other kinds of milk?

Sans had a lot of questions, but few answers, and the answers he did have weren’t all that helpful either. He had to guess and do what he thought was best, trusting his feelings and his ideas even when he knew little about what he was doing. It was daunting. 

For now, he still fed the baby mashed vegetables for the most part, preparing as much monster food in advance as he could, since it didn’t spoil. Then additionally, he would cook human food he foraged from the dump every couple of days fresh. The fridge in _her_ house was always well-stocked now. But he had also decided to add regular monster milk to the baby’s food intake to at least try and emulate its natural diet. He got tired of using a spoon to get all that liquid into the baby quickly, but he couldn’t for the life of him find a bottle. His solution ended up being a clean, unused latex glove he had kept in his workshop in case he needed it. He cut the thumb of the glove off and strapped it to the glass filled with milk, secured it with a rubber band and poked a hole at the tip. It wasn’t perfect, but it worked and the baby could drink from it. It was cumbersome like everything that had to do with the annoying creature. 

It wasn’t made easier by the fact that he was constantly stressed and in a hurry. He couldn’t take too long. 

After the baby was fed, he immediately left the ruins and went back into his room, so his brother could ‘wake’ him and scold him for sleeping too much. Sans would shamble out of his room, looking just as tired as he felt, and join his brother for breakfast. In spite of his lack of sleep, he didn’t want to miss out on time with Papyrus. His brother had for so long been one of the main reasons he got out of the bed in the morning, the only person he really cared about, he couldn’t leave Papyrus alone. Sans would try to act as if nothing was wrong, annoying his brother with puns and praise his breakfast spaghetti like he always did, but he could feel himself slipping here and there. 

Once breakfast was finished, it was time to go to work. His first shift was at his sentry station in Snowdin, just before the door to the ruins. Undyne hadn’t asked about the day when the door had been open, so either Alphys hadn’t seen it on her feed, had mistaken the darkness on the camera for something else, or had chosen not to tell Undyne. Sans wasn’t sure which of those was true, but he kept waiting for the other shoe to drop, and it contributed to the stress he was already experiencing. 

It was difficult for him to work out his emotions in regards to that. If Undyne was informed, if she figured it out… he would be free. No more stress, no more work. He could sleep and wouldn’t have to deal with the mess and the screaming. The last soul would be obtained, and monsters would leave the Underground and gain the sky, the sun, the stars. An existence uncontained by stone walls and independent from the trash that fell down here when humans didn't need it anymore.

And he wouldn’t have to keep looking at the offspring of the human who murdered _her_.

But that would also mean that he would fail his promise. 

Whenever those thoughts came, Sans would slip his hand into his pocket and stroke his fingers over the worn spine and cover of _her_ journal. It helped a little; the weight of a book, the weight of a promise, tugging him down and settling into his bones, reminding him that he couldn’t leave this. He had to see it through no matter what. For his deceased friend.

At his station, he did usually manage to get a few naps in, but they were short. He kept popping into the ruins to make sure to keep the baby fed and cleaned. It seemed that no matter what, there was always something to be done to the thing. Either it was hungry, or it had soiled itself, or both, and sometimes he would also come in and find the baby rolled over and holding itself up by pushing its hands against the ground. It didn’t seem to be moving, but Sans grew increasingly worried that it might start soon and he had no idea what to do then. 

Even his breaks weren’t as restful as they used to be. 

Sans knew that it already looked strange that he worked harder than before - or at least that he pretended to, because when his brother and everyone else believed he was working hard, it was easier to create small moments in which he could disappear to the ruins without anyone noticing, it was easier to explain why he was so tired, it was easier to explain his reading about humans. But Sans also knew that if he changed his routine too much, like say by foregoing his breaks, the impression of his behaviour would go from strange to suspicious, and he couldn’t afford that. 

Not if he wanted to keep his promise. 

It wasn’t a choice. 

So exactly at the same time he always used to, he would go to Grillby’s for brunch. The patrons would all greet him, and he’d make time to say a few words to them like always. He’d order something to eat, fries or a burger, like always. He fed the dogs some scraps under the table, like always. He dared to add a cup of milk sometimes in addition to his ketchup bottle, a plain one instead of a shake, claiming the extra energy from the calcium helped him work more efficiently. 

In truth, he took the paper cup with the milk on the go and carried it back to the ruins with him when the break was over, so he could feed it to the baby. 

Then it was time for his second morning shift in Waterfall. This station was more stressful for him, because it was the one Undyne most often checked personally. Which meant he couldn’t be gone from his post for too long. If the baby started to scream during this shift, he never had much time to calm it. He’d have to visit it in brief bursts, which did little to calm the thing if it really got upset. 

So far Undyne hadn’t caught him yet. 

He kept wondering when his luck would run out. 

After this shift it was his lunch break. Back to Grillby’s, another round of food and small talk and jokes, fake smiles hiding his increasing anxiety and exhaustion. He didn’t even feel all that hungry. The monster food gave him extra energy, but he gladly would have foregone lunch in favour of a good hour of sleep. 

Instead, he attended his two stations in Hotland afterwards, to watch for threats and sell hot dogs on the side. Here, he didn’t have to worry about Undyne or his brother checking on him, and if anyone didn’t find him at one station, he could always claim to have been at the other. But dividing his time between two stations, one of which he had to prepare food at, and the baby back at the ruins, was still just as draining as the constant stress of being controlled. 

The final part of his day was spending time at home with Papyrus. 

At this point he would be ready to fall over and never more again, but if he neglected his brother he felt like he would be breaking yet another promise - one with himself. 

Sans really hated promises. 

After dinner spaghetti, his brother would take a quick shower, which Sans would use to briefly check on the baby again. Most of the time, he would be able to get a final snack in and clean the baby one last time before making sure it was comfy in its nest. With a bit of luck, it would go to sleep then. 

When he returned, it was time to laze around on the couch and watch TV with Papyrus. Despite how difficult it tended to be to actually pay attention to the programme or his brother at this point, this was Sans’ favourite part of the evening. Instead of stressing and worrying and expending magic on dozens of shortcuts, he got to laze around on their comfy, saggy couch and be lulled by the soothing sounds of the TV and his favourite person in the world. This was the good time, the only part of his days that he still actually somewhat looked forwards to. He could at least try to forget his troubles for a while, and instead remember what it felt like to be normal. 

He could pretend there was no baby, no promise, and no risk of being discovered. 

He could pretend his brother was just teasing him when he called Sans a lazybones. 

He could pretend _she_ was still alive, that _she would be waiting for him behind the door tomorrow like _she_ always had, ready for another round of puns and knock knock jokes. _

__

He could pretend he was at peace. 

__

Usually, Sans would doze off somewhere at this point, and be awoken again when his brother carried him up to his room, to place him gently on his mattress, even going through the effort of speeding his creased sheets over him. He wanted so badly to enjoy this that he never told his brother that he was awake, instead pretending to be asleep just so he could enjoy the feeling of having someone who loved him care for him. To have someone else take responsibility for once. It was selfish, and not something he could do when it came to important stuff. He would gladly work himself to the bone to pay for their house and the food if it meant that Papyrus had enough time to train and pursue his dream of joining the guard without trouble. He was working so hard on it too, apparently having taken Sans’ faked increased workload as a reason to double down on his own efforts. 

__

It was just that with the added stress of the baby, it all felt like too much. He was so tired.

__

Especially since, when his brother left to retire for the night, Sans… Sans went to check on the baby, one last time. Because the baby didn’t always fall asleep right away, and sometimes not even the extended TV time with his brother was enough to lull the infernal creature to sleep. 

__

Sometimes, he would return to the ruins and find the baby screaming again, and he’d have to actually work to make it go to sleep. He tried to calm the baby by petting its head or its tummy, but that didn’t always have the desired effect. It could take hours until the thing finally gave up and fell asleep.

__

He hated this. 

__

He was hating it now, two weeks into his new routine, the squirming, crying baby underneath his hand. It was past midnight by now and Sans just wanted to return home and go to sleep, but the baby wouldn’t calm down no matter what he did. 

__

“please, just stop,” he begged it, despite knowing that this did nothing to soothe it. The baby, if anything, only got louder, kicking its chubby legs and shaking its tiny fists in a clear gesture of distaste. 

__

Sans didn’t know what it wanted. 

__

It was fed. 

__

It was clean. 

__

It was not sick, as far as he could tell. 

__

It was not hurt. 

__

It even looked tired, so _why_ was it screaming? Why wouldn’t it just sleep and save both of them the aggravation? All of this could be so easy, and the baby just had to go and make it difficult. 

__

With a groan that spoke not only of his exhaustion and his distaste for the situation, but also of his intense dislike for the creature in front of him, he decided it was time for drastic measures. He leaned forwards and picked the baby up, settling it in his arms. He didn’t like this. He had carried the baby initially, but over the past weeks, he had just left it where it was and tried to touch it as little as possible. It was nothing but a filthy, loud creature after all, whose parent had murdered his best friend. There was no reason to like it or get close to it. He was fulfilling a promise, nothing more. 

__

He lazily swayed back and forth, muttering curses under his breath. The baby was still screaming, but it did get at least a little bit more quiet. 

__

“i hate you,” Sans told the baby quietly. “why do ya gotta be like this, eh?”

__

The baby let out another wail and hiccuped.

__

Sans moved his hand to pat its head, thinking that maybe the combination of movement and petting might finally do the trick. Instead, the baby grabbed onto his phalanges, its crying finally dying down into a series of sniffles and gurgling noises. 

__

“huh,” Sans said, staring at the baby in surprise. It clung to his phalanges and watched them with a focused expression, patting the bones with one hand while keeping a firm grasp with the other. It’s fingers were slightly sticky, but it was finally quiet and so Sans was willing to endure that for now. 

__

The baby continued its exploration at an unhurried pace, concentrating intensely on its actions. Each bone of his had was touched and looked at, each ridge and dip poked, each connection tested. It didn't look like it was about to fall asleep though. What should he do? It was far past the time he would normally fall asleep at, he had to get up early to take care of the baby again tomorrow and his day would be long and stressful again. He desperately needed sleep, and it couldn't be good for the baby either if it stayed up too long. It would probably mess up the entire schedule he had worked out. 

__

“Abbeh,” the baby said, and finally looked up at him. Its brown eyes were wide and questioning, looking up at him with curiosity. “Bffff.”

__

“is that so,” he said listlessly, still hoping the creature would just fall asleep soon. 

__

“Bbllll.” The baby continued to make a small collection of babbling sounds, ending with something that almost sounded like a small giggle. 

__

It was the happiest sound Sans had ever heard from it and it made him pause. 

__

He had missed something. Something important. It was blindingly obvious in hindsight, but he disliked interacting closely with the baby so much and had been so tired that it genuinely hadn't occurred to him up until now. He had neglected the thing, in a way. True, he had been working his tailbone off to make sure the baby’s needs were met, but he had only focused on the physical needs. Food, cleanliness, comfort, sleep, those things. 

__

But he hadn't considered the intellectual side. 

__

As much as he hated to admit it, humans and monsters were not entirely dissimilar. They both needed mental stimulation in addition to their physical needs as far as Sans knew. And he had left the baby on the floor to without anything to entertain it day in and day out, had barely spoken to it if at all, for two whole weeks. No wonder it was desperate for some distraction now, even if it was just his fingers. He would have to think about how to entertain it on top of everything else. As if he wasn't exhausted and overwhelmed enough already. A groan managed its way out of his throat.

__

The baby was still playing with his fingers, unaware of his troubles concerning it. The baby was a creature of the here and now, with simple desires and thoughts. It was hungry so it wanted to be fed, it was bored so it wanted to be entertained. It didn’t care about his exhaustion or inexperience, didn't have a concept of how its existence and demands affected others. It was entirely selfish not out of spite, but merely out of youth. 

__

That sort of made it harder. Sans almost wished he could see it as a creature of evil and blame it for his own misery, but of course that was ridiculous. 

__

It was a baby. It couldn't really be blamed for anything. 

__

Sans sighed deeply and wiggled his fingers above the baby's face. It giggled happily and tried to hold onto him harder, the pressure of its tiny hands on his phalanges increasing. The high-pitched sounds it made were what he would have called cute under any other circumstances. But he didn't find it cute. He was tired and he wanted the baby to sleep and its parent had murdered his best friend in cold blood.

__

He knew that wasn't the baby's fault either. 

__

But it was so _hard_ not to blame any human available for that, no matter how irrational the thought was. And he was taking care of the thing regardless, so what did it matter if he didn't like it and blamed it?

__

Well, it had made him neglect the baby when it came to entertainment, for one thing. 

__

He wiggled his fingers again, watching as the baby smiled and giggled once more. 

__

Fine.

__

Maybe he'd try and stop blaming the baby. He'd _try_. But he still felt resentment and blame directed towards it, even as he kept playing with it where it was settled in the crook of his arm. It would probably take him a while before he would be able to stop feeling as if it was at fault for what happened even if he promised himself to work on his feelings. It may have been two weeks, but the death of one of his closest friends, even if he had never seen _her_ face, was still too fresh. He missed _her_ and the easy interactions they had shared before. The baby technically didn't do anything, but it still felt as if it had taken that away from him. If _she_ hadn't cared so much about humans, maybe _she_ would even still be alive. 

__

No, he said he would stop thinking like this. He had to keep his promise. He had to do what _she_ would have wanted him to have done. In his arms, the baby yawned and inspired a small flicker of hope inside of him that maybe, it wouldn't stay awake much longer. He really wanted to go to bed by now too, his body desperately craving rest. 

__

It still took another half hour before the baby finally tired itself out and fell asleep, and another fifteen minutes before he dared putting it down onto the blanket and pillow nest on the floor again. 

__

Sans fell onto his mattress as soon as he took a shortcut back to his own room and was out in seconds.

__


	4. The Legendary Fartmaster

The baby started crying even more than usual, which Sans would have sworn to be impossible before this point. It was fussy and often refused to eat, leaving Sans at a loss for what to do. 

It had to eat in order to grow properly and not get sick, that much he had been able to figure out. He often had little time to feed it in the first place though, so the more it resisted, the harder it became for him to actually get enough food into it during the time he was in the ruins. He couldn’t just leave it to starve, but more than once he had to leave it hungry and screaming in order to make sure his absences from his post weren’t too noticeable. It was already risky. 

As if this wasn't enough, he also came into the ruins more and more often to the sight of the baby having rolled onto its stomach, propping itself up with its arms, sometimes bobbing up and down or flopping forwards with something close to actual movement. This had happened before, but not so persistently and not with so much additional movement. It seemed to be on the verge of figuring out how to crawl. Sans had hoped that wouldn't happen for a while yet. How was he supposed to leave the baby alone now? If it moved around the room by itself, it could get stuck somewhere or get hurt, and he wouldn't be there to do anything about it. 

He’d have to take safety precautions. 

The thought of changing anything substantial in _her_ house bothered him immensely, but he was sure that _she_ would have wanted the baby to be safe and taken care of more than anything else. So one night after his brother had carried him to bed, Sans got to work. He would have preferred to do this during one of his days off, but the baby progressed too fast for that and Papyrus didn't have any hangouts planned with Undyne during his and Sans’ next day off, so Sans couldn't vanish without being noticed. 

He started by carrying the toy box out of the children's room, mentally apologising to _her_. He didn't throw it out of course, instead relocating it into _her_ room for now. Then he began moving out the rest of the furniture; the cupboard and the bed he added to the free space to the right of _her_ room, the bookshelf found a place in the hallway next to the kid’s room, the lamps he added to the living room so he wouldn’t have to light a fire every time he needed light there. The box with the children’s shoes he put into _her_ room as well. The picture of the flower and the plushies he left as they were. 

He felt _she_ wouldn’t have minded letting the baby use this old stuff. 

Now that the room was cleared out, he sealed the power outlets with the strongest duct tape he could find and added every carpet and blanket he could find to the floor until the entirety of it was covered in a thick, soft layer. He stuffed the corners with pillows and plushies. 

Everything was soft now and he couldn’t find a single thing that might hurt the baby. Save for bumping its head on the wall perhaps, but there was nothing he could do about that right now. Perhaps he might be able to find more blankets or pillows to line the walls with in the future. Like some sort of padded room that would keep the baby safe but still allow it to move while he was away. Perhaps. But that was then and this was now. This was the best he could do. 

With a satisfied nod, he went over to _her_ room and picked the baby up, cradling it in his arm and letting it play with his fingers while he carried it over. Sans decided to walk on foot this time, hoping that the swaying motion would help soothe the baby, maybe lull it to sleep. He placed it in the middle of the room after it had tired itself out, and he felt a rare sense of satisfaction for a job well done. 

Leaving the baby alone wasn’t a good solution, but with the room prepped like this it would be as safe as possible at least. It meant he felt somewhat calm when he returned home, exhausted but content for once, and he fell asleep quickly. 

His head barely seemed to have touched his mattress before his brother was knocking on his door, calling out for him and wondering if he was okay. Damn. He must have slept right through his alarm with how late it had gotten yesterday. Frantically, he scrambled off his mattress and threw on his hoodie jacket on top of the same shirt and shorts he had worn yesterday, which he had also slept in. During breakfast with Papyrus Sans was tense, uncomfortably aware that with having missed his usual first visit to the ruins in order to clean and feed the baby, he would probably arrive to another cacophony soon. He didn’t look forwards to it, and Papyrus noticed something was off. Sans told him he hadn’t slept well again, which was true enough, and then felt nothing but self-hatred when that didn’t help soothe his brother’s worries. 

True to his own prediction, the baby was raising hell when he went to the ruins after breakfast. 

He cursed under his breath, immediately going through the usual routine, first cleaning the baby - and it was really necessary, the underwear he had sewn for it was soaked to the brim, almost leaking through onto the blankets - and then feeding it. Or trying to feed it, in any case. It kept crying and fussing and refusing the food and milk he offered it. He didn’t know what to do, wasn’t it hungry? How was he supposed to make the crying stop if it didn’t accept the usual solutions? 

Experimentally, he began rocking the baby where it lay in his arms, eventually even going through the effort of standing up and walking back and forth while doing so. He had seen monsters rock their offspring to calm them. He wasn’t sure how that was supposed to help, he’d tried swaying it so far and the constant abrupt movement seemed annoying to him, but it was all he knew so that’s what he did. And walking had seemed to work yesterday too, so hopefully it would work again.

The piercing shriek eventually became a desperate wail, which wasn’t ideal but still a marked improvement. He tried feeding it again and this time it accepted some of the food, even though it kept crying the entire time and never accepted the spoon on the first try. It would pause only briefly to accept some spoonfuls of the pureed carrots he kept feeding it, only to then immediately continue, small tears streaming down its reddened, overheated face. 

“ugh, just shut up,” he grumbled. 

He stayed up late to make this room safe for it, he hadn’t slept enough, he was tired and his skull was starting to hurt from the exhaustion and the noise. 

But of course, the baby kept going. 

A while ago, he would have insisted that he’d be too proud to beg a human for mercy. 

Now, he had to reconsider that notion, and to his own shame the desperation won out. 

“please. _please_ stop crying.”

The baby used this very moment to let out an indignant shriek, smacking the spoon out of his hand and sending carrot puree flying everywhere. The blankets and carpets he had piled on in its room all got soiled, his jacket, shirt and shorts got stained, his skull and hands got spatters on them. 

He stared blankly at it, at the stains and the spoons and then back at the baby. Stared and stared and stared. It was still screaming at the top of its lungs with no end in sight. He laid it down. He had to clean the stains. 

Popping over into the bathroom, he fetched towels and damp cloths along with some soap. If he was fast, he might get the stains out before they turned the fabric permanently orange. He returned to the baby's room and began scrubbing at the spattered carrot mash, taking care to be thorough. 

The baby wailed while he worked.

One stain gone, two stains gone, three...

His movements slowed. 

Eventually, he stilled completely. He was kneeling right across from the baby, staring at it without really seeing it. 

“i can't do this,” he mumbled. 

And that, that was the complete truth. 

He couldn’t go on. 

He was so tired.

What was the point anyway? Soon, it would probably all reset. Another timeline unraveled. That was how it had always gone in the other timelines, according to his machine. This was the longest a timeline had gone on, probably, but that only meant that the end must be near. It didn’t matter if he stopped caring. Nothing mattered. 

It was all the same.

The baby's screams were the only reply to his statement. It was beginning to sound hoarse again, the wailing painful. It's face was red and its little body was shaking and shivering from the effort. It seemed exhausting. Sans felt like screaming too, something deep inside of him was sharp and painful like jagged glass that needed to claw its way out of his soul and up his nonexistent throat to burst past his teeth and join the cacophony in the room. 

But he just didn't have the energy. He merely sat and stared at the baby, his mind completely blank. 

It was almost soothing. 

Meditative. 

The wailing became white noise in the background, blending in and out and feeding the grand, white emptiness in his skull. He saw but didn't look, heard but didn't listen, was aware but didn't think, experienced but didn't feel. 

He was lost. 

Perhaps in himself, or perhaps outside of himself. Maybe a little bit of both. In any case, another human could have fallen and made its way through the Underground, the barrier could have shattered in a burst of sound and magic - he wouldn't have noticed. 

The baby sounded painful, its crying now ragged and slightly more quiet. 

And then, while they were looking at each other. Sans completely absent-minded and the baby still crying. 

It happened.

The baby let out the biggest, wettest, most _disgusting_ fart that Sans had ever heard in his entire life. 

It was a fart of such massive proportions that it not only shook Sans out of his numbness, it also rocked the entire body of the baby, its chubby arms and legs twitching from the strain. It was so loud that if he hadn't known better, Sans might have believed the whole mountain was coming down in a rockslide of wet baby poop. 

The baby was shaken out of its own crying. 

It looked at him with an expression of shock, almost horror, and utter disgust. 

And it kept going and _going_. 

When it was finally over, sputtering out like a motor running out of fuel, he and the baby stared at each other. 

Then Sans began to laugh. 

He laughed like he hadn't laughed in weeks, months, perhaps even years. Tears were running down his face and he slapped his femurs, doubling over and almost choking on his own laughter. It was the kind of laugh where he got almost hysterical and his voice abandoned its usual low register, becoming high pitched and wheezing instead. 

The baby began crying again, though this time it wasn't as sharp and loud as before. Just a normal unhappy baby cry. Probably the shock. 

Still giggling, he decided to do something about that. He shifted out of his kneeling position so he sat back on his coccyx and pelvis instead and sighed in relief when the pressure was taken off his patellae. 

“c’mere,” he chuckled, “don't cry. you’re a proper legendary fartmaster if i’ve ever seen one, ya should be proud instead of scared. what an earth shaker.” 

And he picked the baby up again. Began rocking them slightly and wiggled his phalanges over their head. They didn't really calm down much, but they were looking at him and grabbing at his phalanges, so perhaps they would soon. Such a funny thing, that despite everything his hope didn't seem to have died completely yet. 

He didn’t understand it, but he would take it.

“you know, i got a brother,” he told the baby. He didn't know why, it wasn't as if they could understand him. But here he was. With how he was keeping this a secret and with the death of his friend, he suddenly didn't have anyone else to really share his thoughts with anymore. And besides, he had already noted they needed more mental stimulation. Might as well be this. They probably had to learn how to talk too at some point. “he's called papyrus. coolest guy i know, you'd love him. he was a loud kid too.”

Sans pondered that for a bit. 

“actually, he's still kinda loud, heh. think that's gonna be you too, huh?” 

They sniffled and finally stopped crying, blinking up at him with big, wet eyes. 

“yeah. maybe not. hard to say, huh? but, you’d probably enjoy shouting around with him. the other small kids in snowdin love it.” 

Another pause. 

“ ‘course, the older kids think he’s embarrassing. some of the adults too. shitheads.” 

The baby gurgled, bopping his phalanges with their tiny fist. 

“yeah, sorry. shouldn’t swear in front of ya, huh?” 

The baby pulled his phalanges to their mouth and began sucking on them - no, not sucking. Almost more like chewing. It was a weird feeling; their gums were soft and wet and sticky. But he could swear he felt something hard underneath there, too. 

“huh.” 

He began rubbing the tip of his distal phalange over the lower gum, feeling for that hardness. It was right there underneath the flesh. Pressing gently downwards, he managed to get them to open their mouth. It wasn’t easy to see anything there, tiny as their mouth was, but it looked like there were some vague shapes there too. 

“are ya growin’ your teeth?” he wondered. “that why you so unhappy? well, apart from that massive stinker you ripped.” 

He grinned down at the baby. They looked up at him curiously and then hesitantly smiled back, their toothless mouth stretching into an open, happy affair. They made these little noises too, similar to sounding breathless or just on the verge of starting to laugh. 

“heh. actin’ all cute now. ya ain’t gonna fool me, i know what kinda gas you’re made of.” 

The baby's smile widened. Okay, they really were pretty cute, fartmaster or not. Actually, the fact that they could rip one like that made them only cuter in Sans’ opinion. Didn't even need a whoopie cushion. Big toot like that, and then growing teeth on top of it, it was probably no wonder that they had screamed so much. They couldn't just tell him what the problem was after all. 

How long would it take to teach them how to speak? A couple of weeks at most, right?

“look, ‘m sorry if i was a bit mean to ya, okay? do me a solid ‘n don't tell anyone.”

“Agbll.”

“thanks, buddy.”

He allowed them to chew on his phalanges some more, making soft, strained noises all the while. It seemed to help them. He used the opportunity to feel their underwear, and of course they seemed to have soiled themselves when they let out that barrier breaker. He cleaned them and even managed to feed them some more, before deciding that he should try to calm them so he could go back to his daily routine. He didn’t want to be late.

Sans reached over and grabbed one of the stuffed toys he had left in the room - of all the things it could have been, it was a bunny. Worked for him, he knew just what to do. If he was lucky, it'd help them fall asleep. 

“hey, look here kiddo.” He waved the bunny in front of them. “you already know peek a boo with fluffy bunny? betcha don't.”

The baby gurgled. 

“knew it. so, it goes like this. look over here, there's fluffy bunny, the softest bunny in bunnyland…”

It was easy to tell the story, even without having the picture book on hand. Sans had read it to Papyrus so often that they both knew the entire thing by heart. It was familiar and comforting and he soon fell into a rhythm, the well known words rising and falling and lulling the baby to sleep. It was working.

After all that the aggravation, he was suddenly left with a softly snoozing, floppy little bundle of a human. 

“there ya go,” Sans mumbled quietly. “works like a charm every time.”

The baby didn't even stir when he placed them on the blankets. There were still some stains on the blankets, so he cleaned those up. It was probably too late for them, they would have orange spatters all over. His fault for not managing to clean them all immediately. Then again, maybe he could find something in Papyrus’ cleaning supplies. His hoodie had gotten some of those stains too and he didn't want to give up on that yet. He loved his hoodie. It was comfy. 

Come to think of it, he couldn't go back to his station like this. So, put the rest of the food away, wash up to clean his phalanges and skull, back to his room for new clothes, and then back to his station. 

He made it to his room before he noticed that he didn't have another hoodie to replace the one he was wearing. Well, shit. 

Changing into a fresh pair of shorts and a new shirt, he took his soiled clothes and popped into the bathroom where the washing machine was. He stuffed his dirty clothes into the machine, added some of the washing powder for extra persistent stains, and turned the machine on. There. Easy peasy. Now he only needed another jacket and a good excuse for why he wasn't wearing his hoodie, and he could go back to his station and pretend he had been there the entire time - 

The door flew open and Papyrus was standing there, staring at him with wide eye sockets. 

Sans felt like a deer caught in the headlights. 

“SANS! WHAT ARE YOU DOING HERE? WHERE HAVE YOU BEEN?!” Papyrus looked down and stared at the washing machine. “ARE YOU DOING THE _LAUNDRY_?!”

“uh… my hoodie got dirty?” Sans offered, suddenly feeling insecure. 

“WHAT HAPPENED?” Papyrus seemed uncharacteristically upset. “YOU WERE GONE THE ENTIRE DAY! NOBODY COULD FIND YOU! I TRIED CALLING YOU AND YOU DIDN’T PICK UP! I WAS VERY WORRIED SANS!” 

Papyrus stomped his foot against the floor in anger, but Sans could see the tears gathering at the corners of his brother's eye sockets. 

“oh.” 

He felt guilt wash over him. Had he really been gone that long? He hadn't noticed at all. When had that happened? He had just fed the baby, and cleaned up some stains and played with them. There was no way that brief moment of whiteness in his skull could have taken several hours, like his brother seemed to imply. Right? But, Papyrus wouldn’t be this upset if he didn’t have a good reason. 

This wasn’t the expression of someone mildly annoyed. His brother looked _scared_. For him. For Sans. Because Sans hadn’t come home and nobody had been able to reach him. Did he forget his cellphone or did he just not hear it? He actually had no idea. 

He had messed this up. 

“i’m sorry, pap. i went into the forest to take a quick nap, but i must've slept longer than i thought.”

This was barely adequate as an explanation, but what else did he have to offer? Nothing. He couldn't bear to look at Papyrus’ disappointed and worried face, so his eye lights dropped to his feet instead. 

The washing machine rumbled on next to them, filling the small bathroom with white noise.

“THAT'S ALL?” Papyrus questioned. 

Sans wanted to throw himself off one of the waterfalls. 

“yeah. that’s all.”

He could feel his brother staring at him, taking in his posture and his entire appearance. 

“OKAY,” Papyrus raid eventually. 

Sans dared to glance up, only to find his brother still staring at him, the darkness in his eye sockets piercing. It was pretty clear that there was some level of doubt there. Papyrus might not have been able to read faces as accurately as Sans could, but he was good at knowing what made people tick. Once he had gotten to know someone, Papyrus would know what someone's usual behaviour and reactions were, and he knew exactly which buttons to push in order to get what he wanted from them. 

Papyrus knew Sans was acting unusual. And he knew that nothing would work as well on Sans as disappointment. 

He'd be angry at his brother for trying to manipulate him like this, but truth to be told Sans knew he deserved it. He made Paps worry by vanishing the entire day. His behaviour was just plain bad. 

“i just needed a break, you know?” Sans tried to explain. Technically that wasn't even a lie. He had needed a break. “i didn't mean to nap for so long. didn’t even know that much time had passed. you know how it is, i haven’t been sleeping well, so i thought i could just… i’m sorry.”

“ARE YOU REALLY SLEEPING SO BADLY?” Papyrus asked, his voice almost approaching something resembling normal. For Paps, that was uncharacteristically quiet. 

“yeah,” Sans mumbled. It wasn’t a lie, he told himself. It was okay to say this. He wasn’t lying. 

“AND SNEAKING INTO THE FOREST TO SLEEP HELPS?”

“yeah.” It didn’t. He wasn’t sleeping. Didn’t go into the forest. It was the baby, but… he couldn’t say anything, could he? His brother wanted to become part of the royal guard. To catch a human and impress Undyne. To free all monsters and become a hero. If he told Papyrus, then the baby would die. Not because Papyrus had it in him to kill anyone, but he would hand it over as duty commanded, not knowing what it entailed, and Undyne and Asgore had no such qualms. And even if Papyrus knew what his king and his best friend wanted to do to the baby… Papyrus believed the best of people. Always. He’d still do it, hoping it would work.

His brother was fidgeting now, wringing his hands and looking away from Sans. It was clear that Papyrus still felt worried, and it only made Sans feel worse. Regardless of his own feelings, Papyrus apparently decided not to press the matter further. 

“I SEE. I SUPPOSE YOU HAVE BEEN WORKING VERY HARD RECENTLY. THAT MUST BE DIFFICULT WHEN YOU’RE NOT SLEEPING WELL.” 

“mmh.” 

“WELL! IN THAT CASE! I HEREBY DECLARE AN EVENING OF BROTHERLY CARETAKING!” 

Papyrus threw himself into a dramatic pose while Sans stared at him. Apparently, Papyrus had decided that all Sans needed was a bit of brotherly affection in order to help him, knowing that nothing helped Sans sleep like Papyrus could. 

Only, Sans already knew it wouldn’t help. He’d fall asleep, and then later wake up and he’d have to go check on the baby again. He’d be just as tired tomorrow, and the day after, and the day after that… 

He couldn’t tell his brother. 

Papyrus looked so painfully eager to help. 

Sans didn’t feel like he deserved it, not even telling the truth about his predicament. 

“that sounds great, bro,” he said, trying his best not to show how futile he thought this was. He did appreciate the thought after all. He loved his brother, he desperately wanted to soak up all that familial affection. 

“GREAT! THEN START BY TAKING A SHOWER, DON’T THINK I DIDN’T NOTICE THAT YOU SKIPPED AGAIN! I’LL COOK YOUR FAVOURITE SPAGHETTI IN THE MEANTIME! AND THEN WE’LL EAT ON THE COUCH LIKE THE HEATHENS WE ARE AND WATCH WHATEVER YOU WANT ON TV!” 

“ok. thanks paps.” 

He watched Papyrus beam and dash out of the room, lost in thought. The crushing feeling of futility that had already taken him under earlier this day threatened to rise. And that made him wonder about something.

Sans closed the door, locked it. 

Then he took a shortcut into his private workshop. 

Just a quick check, he wouldn’t stay long. 

He shuffled over to the machine, flicking the screen on to look at the numbers representing the timelines. It was the only part of the machine that worked at all. His eye lights flitted over the lines and lines of information, staring in disbelief at what he was seeing. 

The timeline hadn’t been tampered with in several weeks now. 

Before that, he could see the numbers dancing, timelines starting and stopping, looping around, and ending, the patterns of loads and the earlier timelines that had been reset. But then all of that suddenly stopped. No more abnormal repeating numbers, no more divisions by zero, nothing at all in terms of temporal manipulation. It was as if whoever or whatever had been responsible for it - the anomaly, as he liked to call it - had simply dropped everything a couple of weeks ago. 

It didn’t make sense. What happened?

He shook himself out of his surprised stupor and flipped the screen off, immediately taking a shortcut back into the bathroom. Couldn't let Papyrus notice something was off _again_. He turned the water on and and stripped while his thoughts were racing. 

In comparison to the earlier data this was very unusual. The timeline had never been left alone for so long. Not in earlier timelines either. So what was different now? What was the anomaly planning? Preparing for a reset? But why the need for preparation? Something else? Something yet unknown? _Was_ there even anyone planning something, or was it just a force of nature, acting randomly and with no thought behind it at all?

Sans stepped under the shower, barely noticing the heat of the water. He dearly wished he could actually remember what happened in the loads and the resets, to have images and sounds to try and make sense of his situation with. But he had nothing, no memories at all. Just strings of numbers, data points on a screen. They only told him what happened in the broadest strokes, but nothing about the whys and hows. It was incredibly frustrating and depressing. 

But if the anomaly wasn't doing anything… 

A thought crept up on him. 

One that he didn't expect to find so scary. 

What if the anomaly would never load or reset again?

That should be a good thing. Sans should want that. Time moving forwards, that's how it was supposed to be. Just a straight line from start to finish. Things happening in the right order without ever repeating, event A followed by event B and so on all the way to Z. That was the order of things. Normal.

But after all this time of knowing there were ultimately no consequences to his actions, could Sans really go back to that kind of permanence? 

He'd have to try and find out more. Mentally, he calculated the times from now to the last load and figured out when it had stopped happening. It seemed that the very last load was on the day before the human and the baby fell into the Underground. There had to be a correlation there. It was impossible for these things not to be correlated. Since he was already taking care of the baby, it should be easy to see if they were unusual somehow. And he had buried their parent, so he could try to gather clues from them as well. It would be a little harder since he only had his memories of their corpse to go on, but he was clever. 

Sans would figure this out.


	5. Dada

**Notes for the Chapter:**

> I completely forgot to update this before I went on holiday o-o' I'm sorry! Regular updates are back now though, once a week or once every two weeks!

Sans couldn’t figure this out. 

It didn’t make any sense no matter how he looked at it. 

The baby wasn’t special in any way. They were still just a lumpy little flesh bean that pooped their pants and gave him wet, toothless smiles and little babbles here and there. They had a bright red soul of determination, but that wasn’t special in itself either. He contemplated drawing it out to examine it in greater detail, but he wasn’t sure if that was a good idea. Babies seemed so awfully fragile, strong human soul or no. His memories of their parent’s corpse didn’t yield any special information either, so he felt stuck. 

Who would have guessed that a world without resets would unsettle him so much. 

He was suddenly so keenly aware of the multitude of choices he faced every day, and how each of them was now irreversible. If he made a mistake, if he slipped up about the baby, if he did anything wrong… he would have to be so careful. Secretly, he found himself hoping the loads might start up again. That everything might rewind and perhaps next time, _she_ would make it out alive. Only to then immediately admonish himself for that thought. He shouldn’t want that. Even with _her_ death, the stability and continuation of the timeline should be more important to him. 

(And there was also the uncomfortable realisation that perhaps something similar to his grief had played into the resets, if the anomaly was indeed a sapient creature. That perhaps they weren't so dissimilar to each other, wishing for the dead to return. He couldn't allow himself to be like that.)

He felt torn about whether or not he should really believe that this was it. He wanted to and he also didn’t want to, it felt too easy and too difficult at once. It was enough to make his bones feel itchy from nervousness. 

This didn’t help the perpetual stress he was already experiencing. 

As much as he tried, now that Papyrus had noticed the fact that Sans snuck off for longer times during his shifts here and there, he had become increasingly insistent that Sans tell him where he was going at all times in the week following the day where Sans had blanked out.

“i’m tellin’ ya paps, ‘m just goin’ here ‘n there in the forest, it’s random. i find a nice tree to nap under or somethin’ and plop down for a while,” he insisted while his brother accompanied him to his Sentry station. 

Another consequence of Sans’ day of whiteness; Papyrus was reluctant to let him go ahead by himself now. 

“THAT’S NOT AN ANSWER, SANS! YOU COULD BE ANYWHERE, AND THEN HOW WILL I KNOW IF SOMETHING HAPPENS TO YOU? AND YOU KEEP FORGETTING YOUR CELLPHONE ALL THE TIME AS WELL OR DON’T PICK UP! I’M JUST WORRIED, I WANT TO KNOW WHERE I CAN FIND YOU!” The thing was, Sans could easily see that this was true. 

His brother didn’t do this to annoy him or out of a sense of what was and wasn’t proper to do as a sentry. Papyrus, wringing his gloved hands and glancing down at Sans every couple of seconds, genuinely was worried about him. 

That also made it very clear that, should Sans tell Papyrus about his supposed whereabouts, Papyrus would come and _check_. And then what? 

Sans really hated how this whole secret was creating so much trouble between him and his brother. 

“pap, you know i’m careful,” he told Papyrus softly, making sure to let his voice show all the love he held for his sibling. How much he appreciated that Papyrus cared. That he wasn’t trying to be mean in questioning the motives behind all of this. “where’s all this sudden worry coming from, huh? you suddenly don’t trust your big bro to handle himself anymore?” 

He kept his tone teasing, light, but still loving and gentle. Just right. 

Papyrus looked frustrated though. 

“THAT’S NOT IT!” He stomped his foot without letting it slow him down; easy to do when his legs were twice as long as Sans’ were and Papyrus had been walking slowly for that reason. “I’M ALLOWED TO WORRY ABOUT MY ONLY FAMILY!” 

Something in Papyrus’ posture and tone made Sans stop. 

“pap?” 

Papyrus fidgeted, a motion he had been making constantly since their talk in the bathroom. Something was up. How had Sans not noticed immediately? Had he really been so distracted that he didn’t notice that there were several reasons for Papyrus’ distress? He had to make up for it. His soul began buzzing with worry.

“pap, why don’t you tell me what this is about, huh?” He stepped in front of his brother and forced Papyrus to confront him. “you know my sleeping problems get better and then worse sometimes. so why’s that a problem now all of a sudden?”

“I…” Papyrus shifted from one foot to the other. It really wasn’t like him to be so insecure, which only made Sans feel worse. Papyrus seemed to notice that he was, so to say, acting out of character, and immediately went on trying to hide his troubled feelings. “YOU REMEMBER WHAT I TOLD YOU ABOUT THAT TALKING FLOWER, DON’T YOU?” 

“uh, yeah?” Sans frowned at the sudden change of topic. Why was his brother talking about echo flowers now? 

“WELL! IT’S ONLY THAT I HAVEN’T SEEN HIM IN SEVERAL WEEKS AND I’M BEGINNING TO WORRY!” Papyrus admitted. “IT'S NOT LIKE HIM!” 

“him?” This was new to Sans. He had known about the flower, but not about the fact that there had been pronouns involved. 

“I’M NORMALLY NOT SUPPOSED TO TELL,” Papyrus stage whispered. “IT’S A SECRET BETWEEN ME AND MY FRIEND. BUT… HE HASN’T COME BY IN SO LONG NOW AND I DON’T KNOW HOW TO FIND HIM. HE HASN’T CALLED ME EITHER AND I CAN’T REACH HIM, SO I DON’T KNOW WHAT TO DO!” 

“you have a friend you don’t tell me about?” Sans questioned. This didn’t leave him with a good feeling. Such secrecy wasn’t often a sign of someone with good intentions, and while he trusted Papyrus generally to make his own decisions as a grown man, he knew that his brother was somewhat desperate for friendship and admiration and thus susceptible to deception he otherwise should have spotted. He also had a tendency to see the best in people, whether with good reason or not. 

“YES, BUT ONLY BECAUSE HE IS VERY SHY!” Papyrus explained quickly. “IN ANY CASE, THAT’S NOT THE POINT! I’M WORRIED ABOUT MY FLOWERY FRIEND, SO I DON’T WANT YOU TO SUDDENLY VANISH WITHOUT A WAY TO CONTACT YOU AS WELL!” 

That certainly explained a few things. 

“i’m sorry about your friend. i’ll keep an eye socket open too, ‘kay? and i’ll be more careful with my cellphone from now on. all right?” He and Papyrus watched each other for several moments. 

Sans didn’t want to worry his brother further, but he needed to be able to move without his brother following him everywhere. Papyrus already knew that Sans valued his independence and tended to come and go as he pleased. Sans could see the moment where Papyrus caved under that knowledge and his reassurances. 

“ALL RIGHT. I’LL TRUST YOU, SANS.” 

“thanks, pap.” Sans swallowed the guilt and turned to resume walking. 

They moved along the path through the Snowdin Forest, separating at Papyrus’ station without further trouble. As much as he hated thinking like that, he was grateful to be alone again. He calculated how much time he would have before his brother would inevitably check on him and risked a very quick trip to the ruins. 

The baby was thankfully calm this morning, allowing him to change them quickly and get some milk and several spoonfuls of mashed peas in them before he popped back to his station. 

He’d play with them later. 

After the conversation he just had with Papyrus it would be really bad if he wasn’t at his post when his brother came by; Sans was already glad that Papyrus hadn’t scolded him about shirking his sentry duties and had instead focused on more important matters, like worrying about Sans’ health and safety and that of his flower friend. 

It was really strange, to think that Papyrus would have kept a friend of his a secret. Papyrus was so eager to make friends and to be well liked, Sans would have sworn that there was no way for his brother to keep something so important to him a secret. 

Then again, the importance of that friendship might have motivated him in the first place, if it was dependent on secrecy. 

A flower, huh. 

Sans suddenly felt a shiver working its way down his spine. 

He had been too distracted worrying about Papyrus and the implications of what he had been saying, but now that he had a calm moment to think it over…

Sans had buried a slashed flower in the ruins. 

Could it be?

No. 

Surely not. 

According to what he had pieced together from the evidence and the information in _her_ diary, the flower had been the ‘miserable creature’ that attacked the humans. Sans still didn’t know how a flower could be able to do that. A flower monster perhaps, yes, but monsters turned to dust when they died and the flower had left behind… what? A corpse? 

The uncomfortable sensation he had felt when he first approached that flower returned. He didn’t like this. 

Could it have been something other than a human or a monster? Something new? That was a possibility, although Sans had never heard of such a thing. As far as he knew, monsters and humans were the only sapient beings in this world. 

But if that flower _had_ been the friend Papyrus had spoken about… then one of Papyrus’ only friends was dead, and he had no idea.

And Sans couldn’t tell him without giving his own secret away. 

He ran his phalanges over his skull, pressing hard enough to create a rough scraping sound. It made him feel bad, but he already felt terrible anyway. What a mess he was finding himself in. But no matter how much he racked his skull for a solution, there was just nothing he could say that wouldn't make Papyrus question him. 

It wasn't fair. 

As much as it still pained Sans, he at least had _her_ diary, had been able to join _her_ dust with it so he would have one last memento of his lost friend. He could grieve. Having the diary didn't exactly make things better per say, it still hurt and he still wished none of this had happened, but it helped a little. Papyrus should have the opportunity to know what happened to his friend too. The opportunity to grieve. If that slashed flower was the friend Papyrus spoke of, anyway. Sans didn't know, he was only guessing. 

Papyrus found him like this at his station a while later, skull in his hands and deep in thought, but Sans claimed he had just dozed off with his eye sockets open. He took the resulting scolding without complaint. It wasn't serious anyway. Papyrus sounded gentle and as if his soul wasn't in it; it was more for the sake of routine and comfort that he did it at all as far as Sans could tell. After that, Sans waited a couple of minutes and then took a shortcut into the ruins. 

He'd have some time now before his brother would return -

The baby smiled at him, sitting where he had left them lying down this morning. 

“whoa, hey,” he blurted out, feeling his eye sockets widen. 

The baby giggled happily, their eyes scrunching up. They brought their small hands together clumsily with a clapping sound. Sans sat down heavily across from them, staring at the little creature with surprise and wonder. Just a few weeks ago, they had barely been able to roll over. And now they sat up, all by themselves. 

“look at you, eh? are you growin’ up on me now?” he asked quietly, reaching out with one of his phalanges. He poked them gently in the side, not hard enough to topple them over. Despite how annoying their screaming was sometimes, that seemed too mean. They giggled again and to hold of his phalanges, shaking them around and looking up at him with a happy expression. 

He smiled with them for a moment, but then his grin slowly but surely faded until his face was entirely slack and neutral. 

They were growing up. 

Growing teeth, sitting up, they had made some motions close to crawling already. They'd be moving soon. 

And then?

For the first time, Sans truly considered the long term consequences of this promise he had made. 

The baby wouldn't stay a baby forever. If he wanted to keep his promise and care for them, then he would have to raise them with all that entailed. He would have to teach them how to talk, walk and interact, he would have to see them grow up and instruct them how to read and count and all of those things. How would he do this? He couldn't permanently be here. He had to take care of Papyrus. And this was a secret too, if anyone noticed his absence they would wonder why, and discover the baby… and then what? But even if they weren't discovered. Say he managed to raise them. Then they would be all alone, never able to leave the ruins lest they die and their soul be stolen. It was a cursed existence anyway. It would be best if the baby could just leave the Underground, but that was impossible. Only the soul of a monster and a human combined could pass through the barrier, and he could hardly ask Asgore for his soul just so he could shove the baby through the barrier and be done with it. That wouldn't even help. Then Asgore would be dead and the baby would lie on the ground outside the barrier all alone, where they would most likely die because they couldn't even crawl yet. Even afterwards though… they would be all alone with no knowledge of the world. How would they survive that?

It was hopeless, no matter how he looked at it. 

Maybe he should have killed them before he remembered the promise. Then he wouldn't be in this situation now. But it was already too late and he felt that he had no choice but to try his best. 

It was pointless. It was all completely pointless and yet he couldn’t stop. 

“what am i going to do with you?” His voice was low. The baby was still holding onto his phalanges, looking up at him now with big, questioning eyes. His brief dip into hopelessness seemed to have taken the smile off their face as well. Despite how young and generally unaware they still were, his own behaviour already shaped their emotions to a large degree. 

They looked up to him as their only provider and social contact. 

It scared Sans. Even Papyrus had never depended on him so fully; when Sans had to step up and take care of his brother he was already a teenager and Papyrus just on the cusp of becoming one. Things had often been tough and Sans had certainly noticed that he started to slide somewhere between paternal and brotherly in his interactions with Papyrus. 

But this was a whole different category entirely. 

If he wanted the baby to grow up as well as possible while being hidden in the ruins, he'd really have to step up his game. 

“sorry, kid. ‘m just bein’ moody again,” he told them with a smile. They immediately returned it, imitating his wide skeletal grin as best as they could with their complete lack of teeth. Although they were growing them now, none had broken through yet. Their smile provided a good opportunity to check. 

“ok. so you're pretty happy right now, huh?”

“Ah?” They imitated his questioning tone, their eyes widening. They still hadn’t stopped looking at him. 

“that’s what i thought,” Sans said. If they had to learn how to speak and he was currently the only one they could learn from, it would probably be a good idea to talk to them regularly. He didn’t want to be at fault for delaying their development or whatever. 

Jeez, there were so many things that could go wrong raising a child. 

Breathe, he told himself. One step after the other. 

He’d go crazy if he didn’t approach the whole thing slowly. 

“ok. let’s play a bit ‘n then i gotta go back before paps worries about me again,” he decided. 

“Gbbbww.”

“glad you agree, pal.”

“Bwa.”

“sure thing.” He grabbed the bunny plushie he had used to tell them the fluffy bunny story and waved it around in front of their face. “hello. i am fluffy bunny. how are you.”

He automatically slipped into a higher tone of voice doing this. Truth to be told, he felt more than just a little bit silly waving stuffed toys around and talking all squeaky. But the baby loved it. They kept laughing and grabbing at the bunny, making high-pitched babbling noises of their own and beaming at him with those dark brown eyes. 

“you like that, huh?” 

The baby gurgled and pulled the bunny plushie’s ear into their mouth. 

“yikes. don't chew on fluffy bunny. what are you, a cannibal? not under my roof, buddy.” 

The baby was entirely unimpressed by his mock chiding tone. If anything, they brought their toothless maw down even harder on that poor plush bunny ear. They probably needed something more durable to chew on with their teeth coming. Sans thought about that for a moment and took a shortcut to the kitchen. 

Try as he might, his regular use of the room had left its signs here. There were dirty dishes stacked in the sink that he hadn't gotten around to cleaning yet, the pie rested under a glass dome where _she_ had left it (he took a small slice every now and then as a reward for himself when he made it through a particularly harrowing day) and there were two pots with mashed vegetables still on the stove for easy reheating. The pots were closed so no dirt could get inside and contained only monster food, so it was unlikely to spoil. Opening the fridge, he found himself faced with several containers of leftover human food, already pre-portioned and pre-cooked so it would stay fresh longer, ready to be mixed with the monster food. There were also several peeled carrots and cucumbers, also of the monster food variety, which he kept here especially for the baby to gnaw on. Sans was vaguely aware that fleshier monsters found cold temperatures numbing, so he had tried chilled food to help the baby with their teething pain and it seemed to work. 

He grabbed a carrot stick, closed the fridge and took a shortcut back into the baby's room. They looked somewhat unhappy, but cheered up when they saw him, letting go of the bunny plushie to reach for him. 

“here ya go,” Sans said and handed them the carrot. The baby immediately began sucking on it, rubbing its toothless gums over the surface and covering the carrot with spit. The vegetable looked comically large in their tiny hands. They emitted a couple of strained noises, as if they were working hard. Probably felt as if they were, small and weak as they were. 

“Gnnnh,” they said.

“hold that thought for a second, gotta check my station,” Sans replied and took a shortcut back to his sentry station. 

It didn't seem like Papyrus had been here in the meantime, the only tracks in the snow-covered path were the ones from earlier this morning. Hmm. 

Sans pulled out his cellphone and checked the time; his morning shift was almost over. He had a few minutes at best before his brother would come to visit, and then he had to take his break at Grillby’s, get milk for the baby and pretend to be relaxed, get the milk to the baby and feed them, get to his Waterfall station, and figure out how many breaks in the ruins he could take during his second shift and when, without Undyne noticing. 

The baby had been clean and happy when he left them, they had the carrot to soothe their toothaches, and they had the bunny plushie. They'd probably be good to go for a while, Sans decided. 

He settled in and got comfortable on his chair behind his station. On the shelf under the countertop were a half full bottle of ketchup, and empty one that he still had to replace, two books about humans, and a bag with his sewing supplies. He had started making new clothes for the baby. The leftover clothes he found in _her_ house were all too big and he felt that the baby wasn't comfortable like this, and perhaps also not warm enough. 

_Her_ house had cooled down noticeably since… well. He idly wondered if _she_ had perhaps been a fire elemental like Grillby or something similar, to have caused such a shift in the temperature. Fire magic had to be involved somehow, he figured. 

Right now though, it was too close to the time Papyrus normally dropped by, so he decided not to work on the clothes for now. He could do so later during his Waterfall shift. Maybe. He'd have to see how the timing worked out; if Undyne dropped by too often or the baby got fussy, he wouldn't get around to it. 

Papyrus was right on time, and Sans felt relieved at his decisions. They walked back while talking about their shifts - Papyrus wasn't a proper sentry, but he still manned his self-built ‘station’ and constructed and maintained puzzles in order to deter humans in the hopes that it would prove his competence to Undyne. Sans felt torn about it; on one hand he wanted to see his brother happy and all his dreams fulfilled, on the other he was secretly grateful that Undyne held Papyrus back because the thought of his brother having to face the realities of being a guard in the form of enabling the killing of a human made Sans feel like his ribcage might crack open from horror. 

His brother would not fight or kill humans if he could prevent it. 

Partially, that was why Sans had accepted manning the first-alert station closest to the ruins. Humans had always come from the ruins so far, all six of their collected souls and the first one had fallen there as well back when it was still called Home. Manning the station closest to the ruins was therefore considered risky and not a job many even among the guard wanted to do, despite the supposed prestige of it. Sans never would have considered it, but with Papyrus there… His brother wanted to prove his bravery and honour, and had set up his fake station as close to the first alert station as he dared. Sans would rather encounter any humans coming himself before he'd let it happen to Paps. 

The additional pay for the risk was a nice bonus on top that he gladly accepted. With his three other shifts in different locations (Papyrus had other commitments then away from the forest, so he felt safe to leave) it made for a solid income to pay for the house, the groceries, clothes, repair works on the kitchen after Papyrus’ cooking sessions, the TV and internet connections, some gifts for Paps in the form of action figures or car-shaped beds or books here and there… 

They lived comfortably. 

Sans hoped that his increased troubles with keeping his schedule on track wouldn't lead to his shifts being reduced or given to someone else. He didn't want their lives to change more than they already had. As much as he wanted to keep his promise, he didn't want to sacrifice Papyrus’ happiness for the sake of the baby. 

Sans felt surprised when Papyrus accompanied him to Grillby’s for a milkshake; his brother normally hated the place. He gave his usual order and smiled when Papyrus praised him for ordering milk. His brother may not know that Sans didn't drink the milk himself, but it was still nice. The whole break was nice with Papyrus there, shrieking at his puns and trying not to shiver at the terrible state of hygiene while Sans fed the dogs and patted their heads. 

Afterwards, Papyrus left for his solo training. Sans had noticed that Papyrus had increased the number and duration of his training sessions recently. Where before, Papyrus would ‘train’ with Undyne several times a week and fill the other day with a variety of fun activities, he now focused much more strongly on increasing his strength and magical ability. He still took care of his puzzles and practised ‘battle scenarios’ with his action figures, and he was still a cheerful presence in Snowdin who helped elderly and very young monsters out regularly. But he also trained harder than before and had even asked Undyne for more training sessions, as far as Sans knew. 

He hoped she would keep distracting him with cooking lessons, despite how bad he felt for thinking that way.

Sans took a shortcut to his Waterfall station. Undyne wasn’t there of course. This either meant that she was on patrol and he was safe to take a quick shortcut to the ruins, or that she was lying in wait for him to leave so she could scold him when he returned. 

He really disliked this shift, it was so stressful. 

After a couple of minutes, he decided to take the risk just so he could give the milk to the baby. 

“hey, lookit what i brought - “

The baby made a choking noise, flinching as he popped in and shoving the carrot too deep into their mouth. 

“shit!” 

He was next to them in a second, pulling the carrot away from them and clapping on their back to get them to cough. Just in case. Was there something stuck in their throat? Could they breathe?! 

Against Sans’ rising panic, the baby merely coughed twice, and then immediately reached their hands out for the cup of milk. 

“Ahmmmmh!”

“jeez, kid, don’t scare me like that!” He felt shaky. That was unexpected. 

Stupid baby. Stupid carrot. He really couldn’t leave them alone with anything, could he? He sighed deeply, knowing that it wasn’t the baby’s fault for being so delicate. It wasn’t like he could point fingers here, being rather on the fragile side himself.

Still. 

No more carrots while he wasn’t there. 

He fixed the milk cup with the improvised nipple he had created from the latex glove and fed the milk to the baby, glad that they at least weren’t fussing over their feeding. That made it easier to finish, put the cup away, and return to his post on time, where he appeared seconds before Undyne stepped out from behind a corner, leaving him slightly rattled and sweaty while he swore to her that he had absolutely been at his post and not sleeping. He had to wait a bit afterwards before he dared to go back to rock the baby a little - he had discovered that movement and clapping his hand on their bottom helped them fart, which prevented the kind of buildup that had led to the Legendary Fartmaster Flatulence of Epicness - and change their soiled underwear. 

He managed to spend the rest of the day in what passed for a ‘calm’ day by his new standards. Minimal fuss from the baby, he wasn’t caught by Undyne or anyone who would report his absences to her, he managed not to fall asleep or exhaust his magic reserves before he could replenish them. 

Some weeks ago, he would have called it stressful. Now, he was glad it was working out at all. 

There were still moments where he mentally cursed the baby for making his life so difficult. Or where he cursed himself for having made the promise that lead him here. Moments where he needed to reach into the pocket of his hoodie and touch _her_ journal, to remind himself that _she_ had died in order to protect the Underground from the baby’s parent and that the least he could do in return was to keep his promise to _her_. 

On the whole though, he had fewer and fewer of these moments. He still wished for calm and quiet and less responsibility and more sleep, for her to be alive and for the baby to be gone. But he also accepted the reality for what it was. He had to, if he wanted to do this and raise them properly. 

In the evening, after finishing his nightly ritual with Papyrus, he took one last trip to the ruins hoping that the baby would keep up their good behaviour and fall asleep quickly. If they managed that, then apart from the carrot incident it would have been a pretty good day on the whole. It would also mean he’d get as much sleep as he could possibly get nowadays, and he’d never stop hoping for that.

Fortunately for him, they seemed only a little chatty, but not overly fussy when he arrived. They seemed to have this whole sitting up thing figured out by now, so maybe they had spent the day practising that and were tired by the exercise. 

Please, let them be tired. 

“ya had fun today?” 

“Ah.” 

“nice. good to hear. ‘s time for sleep now though. how ‘bout i read to you again? you’d like that, right?”

“Da.”

“right.” 

After his success with telling them the story of fluffy bunny, Sans had made an effort to look through _her_ books for children's stories. Most of them were for older children - actually all of them were. But the baby still liked to look at the colourful illustrations and listen to his voice and as long as Sans was careful to keep the somewhat fragile paper out of their reach it worked out pretty well. 

“Abdabll,” made the baby. 

“uh huh, sure,” Sans mumbled, taking a brief shortcut to the living room to pick out a book. He chose the one about the mole who wanted to know who pooped on its head. He had already read it to the baby several times, but they liked it and it was just so thematically fitting, Sans found.

“okay, here we go…” he said as soon as he was back in the room. He settled down next to them and took them in his arm, holding the book open with his other hand for them to look at. The baby giggled in what he assumed to be anticipation. 

“the story of the little mole who went in search of whodunit,” Sans began. “when little mole looks out of his hole one morning…”

“Habbbblllll,” made the baby, pointing at the book and grinning a toothless grin up at him. “Bbbababa.”

“oh, so you’re tellin’ the story to me now?” Sans asked, chuckling at their earnest way of babbling at him. 

“dada,” said the baby clearly, still beaming at him.

Sans stilled. 

The baby kept babbling, mixing all sorts of sounds into a long string of incomprehensible baby speak. There was no sign of recognition or true repetition there. The baby didn't understand what they said. They had no idea. They were just a baby still figuring out how to put sounds together.

So, really. 

There was no reason for Sans to feel as if they had reached into his ribcage and squeezed his soul with their sticky, tiny baby hands.


	6. Nobody deserves this

Papyrus was late. 

Sans was pacing in the living room, telling himself that he wouldn’t freak out about it. It would be hypocritical of him given that he had blanked out for an entire day and then told his brother not to worry about it too much. Papyrus should have been here fifteen minutes ago, and that wasn’t much. It was probably nothing. Just Paps and Undyne forgetting the time because they got too enthusiastic about their training or something. Even though Papyrus wasn’t the kind of monster to be late even then… 

It was fine. Sans would wait just a bit longer before he’d make a first call to Papyrus. He could do that. It was no big deal. 

...his brother could call though, couldn’t he? Papyrus had asked Sans to stop forgetting his cellphone, and Sans was actually making an effort to carry it with him now. He even went so far to call ahead if he noticed that the baby was extra fussy; he always took a shortcut to his station so his brother wouldn’t hear the baby in the background and then told Papyrus that something had come up at work, before he went back to the ruins. It sometimes added extra time to the whole process of calming down the baby because they didn't like him vanishing in the middle of calming them, but Sans did it anyway. Surely, Sans could expect the same of his brother, since he was trying so hard?

But then Sans had only started trying harder over the past few weeks. Before that, he hadn’t tried at all, no matter what Papyrus said. He had no room to complain. 

Still. 

It was fine, he told himself again. Twenty minutes now, but that still wasn’t much, practically nothing, Papyrus would be here any second. 

Any second now…

Sans forced himself to sit down on the couch, his cellphone clutched in his phalanges. 

Today of all days his brother had to be late. Sans had thought a lot recently, especially since the baby had started babbling more (and called him dada, that one time. His soul still squeezed when he remembered that, no matter how much he told it to stop. His reaction was completely irrational and ridiculous. And yet his emotions refused to listen to reason). He had a lot of worries about keeping the baby safe, but he also felt that raising them alone was perhaps not the best idea. Sans knew that he was running himself ragged, and the baby would probably need more people in their life at some point. 

So he had decided to try and tell Papyrus. 

True, his brother wanted to capture a human. And he was frightfully naive when it came to assuming that nobody in the Underground truly wanted to harm anyone. Or perhaps not naive per say, but certainly a little too hopeful about everyone being good at heart, especially his friends and king. That was probably Sans’ fault. He had always encouraged that loving brightness in his brother. But, or so he reasoned with himself, if he told Papyrus very clearly about why sentries had to capture humans, what happened to humans who were caught, if he really, really explained it and then showed Papyrus the baby, showed him how small and innocent and defenseless they were… surely then his brother would understand. See why the secrecy was necessary. Accept Sans’ apologies for lying and not telling him at first. Help him keep the secret, and all that came with it. 

He didn’t expect Papyrus to take care of them quite so much. He didn’t even want that, he wanted his brother to have enough time to pursue his passions still. Sans was still entirely willing to bear the brunt of the effort just to make sure Papyrus had all the freedom he needed and wanted. But if his brother knew, then at least Sans wouldn’t feel so guilty all the time. He wouldn’t have to constantly lie to Papyrus, and perhaps his brother could help and cover for him when Sans had to go to the ruins. At the very least, it would give Papyrus an understanding for why Sans was running late and feeling tired so often recently and perhaps soothe some of his worries. 

He hoped it would work out that way in any case. 

But now Papyrus was late and Sans was beginning to worry himself. It was throwing his whole schedule off. He had taken care of the baby and cleaned them and fed them and played with them, to make sure they would be quiet and as cute as possible when he arrived with Papyrus. To make sure that it would go over well or whatever. But if Papyrus was late, it might not work out that way, and then what would Sans do? 

And where was Papyrus, anyway? He’d had a training session with Undyne as far as he told Sans, and Sans knew that Undyne tried not to keep Paps too long because she had her own stuff to do too, like teaching music to her neighbors or pretend that she wasn’t mooning after the royal scientist even though pretty much everyone but said scientist herself already knew at this point. 

So, there was really no reason for Papyrus to be late, unless something had happened to him, which Sans was trying not to think about because he was _not_ going to do the whole overprotective older brother shtick, that just wasn’t him and he knew Papyrus wouldn’t appreciate it - 

The door opened, and Papyrus walked in. 

Sans could have cried, sagging back into the couch cushions, trying to pretend it wasn’t because the tension was leaving him but just because he had been here the entire time, relaxing. 

“hey pap,” he called out as casually as he could. 

“SANS! I AM GLAD YOU ARE ALREADY HERE! I NEED TO SPEAK TO YOU IMMEDIATELY!” 

Papyrus barely took the time to close the door and take off his boots; he was practically vibrating with energy even though Sans could see that he was physically tired from the training. His bones were a bit dirty and scuffed; not unusual after he and Undyne had gone wild in the kitchen. 

“yeah? why, somethin’ serious? didja set undyne’s kitchen on fire again?” Sans chuckled, already mentally preparing himself for Papyrus to ask if Undyne could crash on their couch. That would have some positive and some negative consequences; on one hand it would mean that he’d have to be careful so Undyne wouldn’t notice him vanishing out of the home, on the other hand it would also mean that she’d be distracted by the reconstruction of her house so it might be easier for him to vanish during his shifts. He was still mentally trying to figure out which of these outweighed the other when his brother already continued.

“NO, BROTHER! IT’S NOT THAT, WHY IS THAT ALWAYS THE FIRST THING YOU ASSUME?” Papyrus asked indignantly. Sans forced himself not to mention that he had stopped counting how often that had already happened while Papyrus continued. “NO, I HAVE GOOD NEWS INSTEAD, NYEH HEH HEH!” 

Papyurs puffed up and Sans sat up a little straighter, definitely curious now. 

“oh? ya mastered the spaghetti dish?” he guessed. Hmm. That would mean Undyne would have to think of a new dish to teach. Perhaps he would get to eat something other than spaghetti soon. Lasagna or penne arrabiata. Sans wasn't picky.

“NO! SANS, LET ME FINISH!”

“ok.”

“I! THE GREAT PAPYRUS…”

Sans waited patiently while his brother let the dramatic pause he deliberately created for the extra effect drag on just a little bit too long. 

“...HAVE BEEN INDUCED INTO THE ROYAL GUARD!”

His brother practically screamed the last words, dancing on the spot from the excitement. 

Sans dropped his cellphone in shock. 

“you… what?”

“NYEH HEH HEH! I CAN SEE YOU ARE AWED BY MY ACCOMPLISHMENTS! IT IS TRUE! JUST NOW, UNDYNE HAD ME KNEEL BEFORE HER AND SWEAR THE OATH OF LOYALTY AND DUTY TO THE MONSTER KINGDOM! AND SHE HANDED ME THIS!” Papyrus reached into the pocket of his shorts and pulled out a shiny metal badge, looking just like the one Sans had received when he had been officially employed by Undyne. It was currently lost in his trash tornado, something that surely would not happen to Papyrus’ badge. Sans stared at the badge mutely as his brother continued. 

“I HAVE BEEN WORKING ON MY MAGIC AND MY FIGHTING TECHNIQUES VERY HARD RECENTLY, AFTER I SAW YOU WORKING HARD AS WELL. I HAD ALREADY SET SUCH A GOOD EXAMPLE FOR YOU, I OBVIOUSLY HAD TO CONTINUE! INSTEAD OF OUR USUAL TRAINING, I CONVINCED UNDYNE TO SPAR WITH ME WHEN I DEMONSTRATED MY TECHNIQUES TO HER. SHE HAS BEEN TRAINING ME MORE SERIOUSLY DURING THE PAST WEEKS AND TODAY, ALL MY HARD WORK HAS PAYED OFF! I AM NOW AN OFFICIAL ENTRY LEVEL SENTRY AND CAN BEGIN WORKING MY WAY UP IN THE RANKS, TO PROTECT THE KINGDOM AND CAPTURE ANY HUMANS THAT MIGHT FALL! I WILL PROVE TO UNDYNE THAT I AM WORTHY OF HER TRUST! I WILL CAPTURE A HUMAN AND THEN I WILL BECOME AS POPULAR AND BELOVED AS I ALWAYS WANTED TO BE!”

Papyrus’ eyes were practically sparkling at the end of that little speech. 

Sans stared at his brother and felt his eye lights close to going out. What the hell had Undyne been thinking?! She was not supposed to do this! Papyrus wasn't supposed to be part of the guard, especially not so quickly, especially not _now_ …

How was he supposed to bring up the baby now? Papyrus’ fervour for capturing a human has predictably only been reignited by his new position as a sentry. And his loyalty to Undyne increased now that he achieved his long time goal. If Sans were to bring up the baby now… No matter how he would phrase it, his brother would not be receptive to Sans’ arguments. 

Papyrus was beginning to falter in his enthusiasm, a miniscule change in posture and demeanour that Sans knew well enough to recognise before it even fully got there. 

“i. wow. pap, i don't even know what to say,” Sans said truthfully. He had no words. How could he have words for this, when it destroyed all hopes he might have had of gaining some semblance of support? But at the same time, Papyrus had achieved his _dream_ , had managed to do the one thing he had been talking about and obsessing over for so long now, that he had worked exceptionally hard for and focused all of his efforts on. Sans loved his brother far too much to deny him praise for that accomplishment, no matter how hurtful it was for him personally. So Sans stood up, walked over to his brother, and placed a hand on his brother’s radius and ulna. He made sure to show all the pride and affection he felt for Papyrus while hiding the shock, the worry, the pain. “that’s amazing bro. you did it. i’m proud of you.”

“BUT OF COURSE YOU ARE,” Papyrus exclaimed, scrambling to regain what little falsified confidence had been lost in that brief moment where Sans had sat silent and horrified in the wake of the news. “IT IS VERY IMPRESSIVE, IF I DO SAY SO MYSELF. I AM NOT SURPRISED THAT YOU WOULD BE AWED BY MY OUTSTANDING ACHIEVEMENTS!”

“yeah,” Sans agreed easily, because that at least was true. He would never not be amazed by what his brother could achieve when he really put his mind to it. “keep sayin’ how cool you are. i meant it. you wanna celebrate? i could… make a pie or something.” 

He ignored the pang of grief and pain at the thought of making pie, at using one of _her_ recipes to celebrate Papyrus’ new role as a danger to something _she_ had wanted to protect. 

“YOU MEAN THOSE STRANGE SUGARY QUICHES OF YOURS? I SUPPOSE I CAN INDULGE YOUR UNUSUAL TASTE IN FOODS FOR THE OCCASION!” Papyrus huffed. From the way his eye sockets widened, it was pretty clear though that he actually liked the thought. 

“ok. want me to buy you a milkshake too?”

“THAT SOUNDS WONDERFUL, THANK YOU!” 

The milkshake was purchased quickly and soon enough, Papyrus was sitting at the table enjoying it while Sans made the pie. Papyrus kept chatting away excitedly about how exactly his induction went and the daily minutiae of being a sentry that he felt excited about. 

“SO THEN I BROUGHT OUT MY DOUBLE CROSS BONE ATTACK, BUT SHE EVADED OF COURSE, BUT SHE HAD NOT FORESEEN MY FOREST OF BONES THAT IMMEDIATELY FOLLOWED WITH! IT'S TRUE THAT SHE GRAZED GRAZED ME WITH HER SPEARS BUT IT WAS ONLY A LITTLE BIT, BUT I KNOCKED HER BACK THIS TIME! AND THEN WHEN SHE RETALIATED WITH HER GREEN MAGIC I EXECUTED MY DEFENCE FLAWLESSLY AND FOLLOWED WITH A BONE WAVE!”

“sounds awesome, bro.”

Sans was pressing the dough into the greased pan, making sure it was spread evenly. The kitchen was beginning to smell like flour and sugar, milk and cinnamon, scents that he had come to associate with _her_ to the point where he sometimes wondered if _she_ smelled like that. He thought it might have been a possibility, if _she_ baked a lot. Even though he had recently started to suspect that _she_ was a fire monster of some sort, and thus would most likely smell smokey, he found it hard to let go of that fantasy. Despite the grief that came with it now, he still found the scent generally soothing. 

“did… did undyne say anything? about why she changed her mind?”

The question left his mouth before Sans could even fully wonder if it was a good idea to ask it. Papyrus paused in his recollection of how his sparring with Undyne went and easily switched the topic, apparently happy to satisfy Sans’ curiosity, happy to talk about anything related to his new position. 

“SHE TOLD ME THAT MY RECENT EFFORTS HAD SHOWN HER THAT I WAS READY TO DEAL WITH THE NECESSITIES OF THE SENTRY JOB. SHE HAD BEEN WORRIED ABOUT ME BEFORE BUT NOW IT WAS DIFFERENT!”

Papyrus paused and then, just when Sans wanted to comment, continued after all. 

“WORRIED, CAN YOU BELIEVE IT? I AM THE GREAT PAPYRUS AFTER ALL, WHAT IS THERE TO WORRY ABOUT? I AM VERY GLAD I COULD FINALLY MAKE HER SEE THAT THERE IS NO NEED FOR SUCH THINGS!”

“ready… for the necessities…?” 

Sans couldn’t help but speak slowly. He didn’t like the sound of this. At all. Papyrus was always eager to train and expand on his knowledge and prowess in battle - just like most monsters, he loved a good encounter. For his brother, fighting was a way to showcase his knowledge, magical ability and control. But ‘the necessities of being a sentry’ weren’t just being good at fighting or even just being strong. It was about capturing humans in order to take their souls. To kill them, if necessary. Surely his brother hadn’t demonstrated his willingness to kill to Undyne…? 

Sans couldn’t imagine it. 

Undyne cared about Papyrus too much. Right? 

“YES, SANS! TO CAPTURE A HUMAN! SHE WAS WORRIED I WOULD LET THEM GO! BUT OF COURSE I WOULD DO NO SUCH THING! WITHOUT THE LAST SOUL, WE WILL NEVER BE FREE!”

Papyrus and Sans stared at each other across the kitchen, but they might as well have been separated by an abyss.

“WHY IS EVERYONE SO SURPRISED WHEN I SAY THAT?” Papyrus wondered.

“pap… you know what happens to humans when their soul is taken?” 

Sans had to make sure. He had to. 

“W-WELL!” Papyrus suddenly shifted uncomfortably in his seat. Almost as if he was guilty. He actually turned to look around, before leaning forwards in a conspiratory manner, stage-whispering to Sans as if they weren’t completely alone in the house. 

“I KNOW YOU AND UNDYNE HAVE TRIED TO KEEP IT FROM ME, BUT IT’S ACTUALLY NOT THAT HARD TO SEE THAT UNDYNE’S OPINION OF HUMANS IS VERY… MURDERY. MOST MONSTERS SEEM TO THINK THAT WAY.” 

Sans felt as if the floor was dropping out from underneath him, but Papyrus wasn’t finished yet.

“SO I THOUGHT, AFTER MY INCREASING BATTLE PROWESS DID NOT IMPRESS HER ENOUGH, MAYBE THIS WOULD CONVINCE HER! AND IT WORKED!!”

“i see,” Sans mumbled quietly. He was really trying not to look too disproving, he still wanted to support his brother more than anything, but he couldn’t help feeling as if everything was breaking down around him. It was impossible! Papyrus should not be talking this way. Sans never would have thought that his brother would go this far, would change his own moral principles to such a degree. Popularity and being liked had always been important to Papyrus, but to such an extent… surely there must be something wrong here. He was immediately relieved and hopeful when his brother spoke up again. 

“SANS?” 

“yeah?”

“NOW THAT I CAN WORK FROM THE INSIDE, DO YOU THINK I WILL BE ABLE TO CONVINCE UNDYNE AND ASGORE THAT MAYBE THE HUMANS THAT FALL WON’T HAVE TO DIE? WE COULD JUST USE THEIR SOULS WITHOUT MURDERING THEM!”

Papyrus looked at Sans with hope in his eye sockets, and Sans tried his best not to show how close he was to crying. 

“if anyone can do it, it’s you.” 

Sans had his doubts about whether or not anyone could be convinced to spare a human. But at least his brother had not suddenly turned into a killer. There was something deeply wrong with the world when Papyrus sounded as if he was willing to kill and Sans was glad that his intuition and knowledge about his brother had turned out correct, and Papyrus was merely pretending to be willing to do such a thing. He must have been pretty convincing over the past few weeks for Undyne to have fallen for it. Hell, Sans had almost come close to believing it for a few moments! Enough to be shocked and doubting at least, and that was no small feat. 

Still, with Papyrus’ new position and his ongoing belief that he could convince Undyne and Asgore not to kill a human even after delivering it to them, Sans saw no way to reveal his secret to his brother now. It was simply too risky. 

He allowed himself a small sigh as Papyrus picked his tale of how he had trounced Undyne during their training session today, while Sans himself focused back on his pie. He was soon ready to bake it and used the time while the pie was in the oven to focus better on Papyrus and ask him more question about his new job. 

Apparently, Sans would work under his brother from now on - unusual since he had more experience, had worked as a sentry for longer, and was even manning the first alert station. But Papyrus explained that Undyne said that she didn’t think Sans should have to carry the added responsibility of overseeing another monster, since he was already doing so much. She felt that having someone else take care of Sans’ shifts and such would lighten the load for him and also give Papyrus a good insight into how the guard shifts worked by observing another monster. 

It was a nice way to say that she thought Papyrus would stop Sans from sleeping at or vanishing from his stations. 

Very classy and understated, and thus almost out of character for her. 

Sans didn't know how he was supposed to explain his absences to his brother. Especially now when Papyrus had even more incentive to capture a human to prove his worthiness to Undyne. 

Still he tried his best to celebrate properly with his brother. Pretended to be interested and proud as they talked while the pie baked. Enjoying himself when they both ate the pie, not bothering to let it cool first because they both liked how the fruit filling tasted warm. Reading Papyrus his bedtime story for the first time in a while, and taking actual pleasure from the old and comfortably well-known ritual. 

It was only when he went to his room afterwards that he allowed himself a brief moment where he put his hands over his sockets and drew one trembling breath after the other. 

It was all so much. 

Papyrus had his new position, all of Sans’ plans were suddenly in shambles, he had no idea how he would manage in the future and due to the celebrating in his brother's constant presence he was already running late and the baby would be hungry and probably soiled and crying when he arrived. 

A break would have been really nice, but there was no way to take one. Not without causing more trouble later on. With another deep sigh, he took a shortcut to the ruins. 

The baby was predictably crying, smelly and all around unhappy. 

They reached out for him when he approached to pick them up, surprising him a little, but they didn't stop crying until after he had cleaned them and was feeding them back in their room. They were still sniffling occasionally. He was rocking them a bit here and there, although he tried not to move them too much. Feeding them took priority for now and they sometimes coughed up their food if he moved them too much while feeding them. 

“you good now?” He asked once that was taken care of.

“Gbbl.”

“cool.” 

They were still in his arms, now looking up at him expectantly. It was pretty clear that in some way, they were hoping for him to entertain them, despite the way the yawned while looking at him. Considering that he missed out on looking after them in the early evening like he usually would, because of celebrating with Papyrus, he couldn’t really fault them for that. 

What could he do that they might find entertaining that also wouldn’t wind them up too much?

He didn’t want to shirk on engaging with them, but he had to consider that it was getting late and apart from his own exhaustion, he didn’t want for them to get too excited to sleep and thus messing up their sleep schedule. 

An idea came to him, something he used to do with Papyrus when they were younger. Easy, simple, quick. Didn’t take a lot of effort, but kids loved it. There hadn’t been much opportunity to indulge in this kind of silliness lately, so he actually appreciated the opportunity. 

“bleeeeeh,” he made, sticking his ectotongue out at them while rolling his eye lights. 

The baby looked up at him with a frown, as if they were questioning his sanity, a tiny little fold forming between its eyebrows. 

“aw. c’mon, i’m doing this for you, you know,” he complained, feeling irrationally embarrassed at their reaction. Still, he tried again, this time ramping it up a little by letting his eye lights roll around in his sockets, trying to touch his ectotongue to his nasal bone. 

They reached up and tried to stick their fist into his eye socket. 

“whoa, hold on there, buddy!” Sans blurted out, quickly drawing his skull back from them. Just in time too, or that would have gotten uncomfortable. “that’s not what you do with an eye socket.” 

“Dabl,” they informed him. 

“no, really,” he insisted. 

The baby clung to his shirt, still looking up at him with a sort of skeptic touch on their expression. It was fascinating how expressive their face was at such a young age. For some reason, Sans had never bothered to picture human baby faces as this expressive. Perhaps because he had mostly seen them on pictures and in movies where they were depicted as crying or sleeping so far. The reality only matched that sometimes; there was so much more to a baby than that.

Suddenly the baby began to giggle. 

“oh, deciding to join me now?” Sans raised one of his brow bones and tried again. Eye lights rolling, tongue sticking out between his teeth. “bleeeeh.”

“Eeeeh,” made the baby and stuck out their tongue at him. 

He couldn't help himself, and laughed too. They looked cute like this, he couldn't deny it. They were kind of cute in general. 

“bleeeeh.”

“Eeeeh.”

“this is better than the fart of legends,” Sans decided with a chuckle. “specially ‘cause you can pretty much do this on command.”

The baby looked up at him expectantly and so he did the silly face again, this time shaking his head back and forth so his tongue went flapping around. The baby squealed from joy, trying to grab it. He dissolved the magic, leaving them to look at where it used to be with surprise. 

“you need to learn not to poke people's faces,” he scolded them gently. They merely huffed in response, apparently not pleased with his reasoning. The huff then transformed into a big, long yawn, and Sans felt hopeful that he might get to sleep somewhere in the near future. 

“that’s right, buddy. yawn away.” To drive the point home, he imitated a yawn himself, an imitation which became a true yawn halfway through. “heh. look at us both, yawning away.”

The baby huffed again and then whimpered. 

Sans, not wanting to deal with another bout of crying after the evening had otherwise gone so well, opted for drastic measures and lifted the baby up until their head rested on his shoulder. He could feel their small huffs of breath against his clavicle like this. They felt very warm against his ribcage. Was he too uncomfortable for the baby? He hoped not. 

“there there,” he mumbled absentmindedly, rocking back and forth. “it’s ok. i know you’re tired. just sleep.”

It seemed to help because they immediately calmed down, making a few babbling noises before yawning again and becoming quiet. Sans knew that this was a critical moment; they were on their way to sleep but not really there yet, and any wrong movement or loud noise or worst of all, trying to put them down, would result in more crying. So he kept moving gently, trying to keep up a steady stream of reassurances in the most soothing voice he could manage. 

“imagine all the cool dreams you’ll have, huh? baby dreams. ya can dream of all the mashed vegetables you wanna eat. food’s always a favourite, heh. or dream of fluffy bunny. or…” 

He looked around the room, which was mostly empty save for some plushies and the blankets on the floor. It had to be, in order to be safe, but what a difference it was compared to the rooms most monsters would create for their children, lovingly furnished and decorated. 

“or furniture,” he kept going, telling himself he couldn’t stop despite his sudden strange feeling about this living situation. “dream of all the furniture you’ll be able to have once i don’t have to worry about you accidentally killing yourself by falling off a bed anymore, eh? all the options you’ll have. didya know paps has a racecar bed? maybe you can have one too.” 

He had no idea where or how he would procure another one of those. 

“or dream of just having a bed in general,” he whispered. “or…” 

His stream of reassuring, low mumbles petered out. It didn’t seem to matter; the baby was breathing calmly like they only did when asleep, their limbs loose and heavy. He was still rocking them. Out of necessity, of course. 

Of course. 

“you don’t deserve this,” he whispered, only half aware of what he was saying, overcome by feelings that he never asked for, that had snuck up on him between toothless smiles and silly fart noises and every babble that even vaguely sounding like an address of parenthood. “nobody does. ‘s not right, how they all want you dead. what did you ever do?”

The final absolution slipped past his teeth before he even knew it. 

“it’s not your fault.”


	7. Shifts

**Notes for the Chapter:**

> [Look at this awesome Fanart Three Bones and a Baby has gotten! It's a whole tag!](https://rehlia.tumblr.com/tagged/tbaab-fanart)
> 
> A big thank you to everyone who's reading and interacting with this story x3

Sans and Papyrus left the house relatively early and began walking to their sentry stations together. Sans would have loved to take a shortcut, but now more than ever Papyrus insisted on checking the puzzles in the forest on the way to work, to make sure they all functioned correctly, and that meant walking. It was his official duty now after all. Usually Sans would leave him to it after a bit, take a shortcut to the ruins to check on the baby, and then meet up with his brother again at his station, but today Papyrus had insisted on them walking together. 

He didn’t know why, but Sans had an uneasy feeling that Papyrus wanted to talk about certain specific things. 

Working under his brother was different. It was better since Papyrus was unwilling to make any offence Sans might commit into a threat of firing him, but worse because Papyrus now also felt that he couldn’t excuse Sans’ many nap breaks and other unexplained absences anymore. 

Sans wasn't sure what to do about this. He didn't want to cause trouble for Papyrus now that his brother had gotten his dream job after so long, but of course he also couldn't leave the baby. It posed a dilemma; another one on the giant heap of problems he already had to deal with. He handled it like he handled most things in his life. 

He pushed it to the back of his mind and evaded the topic while hoping it would somehow work out in his favour. 

That was a bad idea of course. But what else was he supposed to do? He was pulled into two diametrically opposed directions with no way to commit to one or the other without there being horrible consequences. He managed to evade Papyrus’ questions about it for perhaps a week or two, and now… and now he couldn't anymore. Papyrus dove right into it without preamble.

“SANS, I KNOW YOU TOLD ME ABOUT YOUR SLEEP PROBLEM AND I REALLY TRY TO BE UNDERSTANDING, BUT IT'S GETTING OUT OF HAND! WHAT AM I SUPPOSED TO TELL UNDYNE WHEN I REPORT BACK TO HER?” Before Sans could even try to make one of his usual quips, Papyrus was already pressing on. “AND PLEASE DON'T TELL ME TO LIE TO HER. HOW CAN I SHOW HER THAT I DESERVE HER TRUST IF I LIE TO HER?”

“i know, bro.”

Papyrus came to a stop in front of his sentry station. The ramshackle building that had served as Papyrus’ sentry station while he was working unofficially was gone, instead replaced by one of the sturdy wooden huts that the regular sentries used throughout the Underground. The canine unit had helped Papyrus and Sans to build it, and Undyne had personally come by to check if it was constructed to the official standards. It had passed the test and left Papyrus with a swagger in his step for the whole rest of the week, chest puffed up in pride. Sans found it both hilarious and cute, even though he was obviously proud of his brother too. Papyrus _deserved_ this. He had given his all and managed to do what he always dreamt of doing, which was more than Sans could often say for himself. 

“BROTHER…” Papyrus stopped himself and glanced around them for a second, checking if they were truly alone. They were; the dogs were all at their own stations and no other monster seemed to be around. Snowdin forest and the path leading through it lay silent, the thick blanket of freshly fallen snow from last night muting the sounds of the forest even further until it felt as if someone had stuffed a thick blanket against their earholes. The air was just a bit colder than usual, the chill of the ice and snow causing the temperature to dip closer to bracing than refreshing. 

“I HAVE BEEN THINKING,” Papyrus finally continued. Sans was almost startled after he had lost himself a bit to his thoughts about the weather. “PERHAPS IT WOULD BE A GOOD IDEA FOR US TO WORK OUT A DIFFERENT SCHEDULE FOR YOU NOW THAT I HAVE BEEN GIVEN MY OWN SENTRY POSITION. I CAN DO THAT AS YOUR SUPERVISOR!” 

Despite Papyrus’ excited tone of voice, Sans could hear the worry underneath and he didn't like it. He liked the suggestion itself even less; if his schedule changed he'd have to work out his visiting times to the baby all over again and who knew if it would even work out properly once more?

“bro, i don't think that's - “

“NO, NO, HEAR ME OUT SANS!” Papyrus was quick to interrupt him. He looked somewhat guilty for doing so, but went on with it nonetheless. “I THINK IT WOULD BE A GOOD CHANGE FOR YOU! YOU'RE GOING TO LOVE THIS!”

Sans wasn't quite so sure about that assessment, but he could tell that Papyrus’ feelings were as genuine as always. He always had trouble denying his brother. Also, if he allowed Papyrus to continue, it would give Sans enough time to formulate a counter argument to whatever troublesome change his brother was going to propose. He just had to stay calm, that was all. 

“ok. tell me,” he prompted, giving his brother a nod. 

Papyrus beamed in return feeling obviously happy that Sans had given in with only a minor amount of resistance. 

“ACHEM! SO AS I WAS SAYING, I THINK THAT A CHANGE IN YOUR SCHEDULE WOULD BE BENEFICIAL TO YOU NOW THAT I HAVE OBTAINED MY OWN SENTRY POSITION! I HAVE DECIDED THAT, AS YOUR OFFICIAL SUPERVISOR IN THE ROYAL GUARD…” Sans waited through this dramatic pause in Papyrus speech just as patiently as he would through any other, even though he felt uncharacteristically nervous about what was coming next. “I WOULD LIKE TO REDUCE YOUR SHIFTS!”

That was certainly not what Sans expected. He felt caught off guard. 

“what? no way. bro, we gotta pay the bills ‘n the house ‘n all of that.”

“I KNOW SANS! BUT NOW THAT I'M A SENTRY, I EARN MONEY TOO, SO IT'S OKAY IF YOU WORK LESS.”

“pap, you don't gotta worry about that kind of stuff,” Sans insisted, increasingly anxious. “i got this.”

“SANS.”

Papyrus placed his hands on Sans’ shoulders. Not in a rough way, he was very gentle actually. But he still held on firmly, keeping Sans rooted to the spot. They stared at each other with similar amounts of serious contemplation in their eye sockets. 

“I KNOW THAT YOU WORKED VERY HARD TO PAY FOR THE HOUSE AND EVERYTHING ELSE. SOMETIMES I FELT BAD ABOUT THAT. AND I THOUGHT, PERHAPS IT WOULD BE BETTER IF I STOPPED TRAINING AND FOUND A JOB TOO, SO YOU DIDN'T HAVE TO BE SO TIRED FROM ALL YOUR WORK ALL THE TIME.” Papyrus held on to Sans and looked even more serious as he continued. 

Sans felt bad. He didn't want his brother to worry about this stuff. He had tried so hard to keep all of this away from Papyrus, pretending to be lazy and that everything was effortless. How could he have failed so thoroughly?

“BUT THEN I THOUGHT,” Papyrus continued, “THAT I SHOULDN'T DISMISS YOUR EFFORTS. YOU WORKED HARD BECAUSE OF ME. BECAUSE I WANTED TO BECOME A PART OF THE ROYAL GUARD. YOU WANTED TO SUPPORT ME AND MY DREAMS. AND IF I DIDN'T ACCEPT THAT, THEN IT WOULD ALL HAVE BEEN FOR NOTHING! I WOULD HAVE THROWN YOUR SACRIFICES AWAY! SO I TRIED VERY HARD TOO. AND NOW I DID IT!”

Papyrus’ expression became softer and less serious now. There was something warm in his eye sockets now as he looked down at his older brother. 

“NOW I CAN EARN MONEY AND FULFILL MY DREAM AT THE SAME TIME! IT'S NOT JUST ONE OR THE OTHER ANYMORE. EVEN IF YOU WORK LESS, WITH TWO SALARIES WE HAVE MORE THAN ENOUGH FOR THE HOUSE AND THE BILLS AND THE GROCERIES! AND SINCE YOU'VE BEEN SO TIRED RECENTLY, AND I CAN CONTROL YOUR WORK SCHEDULE NOW, ISN'T THIS THE PERFECT OPPORTUNITY TO MAKE THE CHANGE?”

“what about the car?” Sans asked, still unsure about this development. Papyrus had obviously given this a lot more thought than Sans would have guessed. He’d had no idea that Papyrus was hiding all these thoughts about Sans’ work for so long. “i thought you wanted to be able to buy a sports car as soon as we got out of here. drivin’ down a highway and all that. that’s gonna cost a lot.” 

His brother made a good point and honestly, Sans did like the idea of having not quite so many shifts to juggle on top of his other commitments. But he didn't want to give up a part of his income to the detriment of his brother. He already didn't like that Papyrus was worried about the whole money issue in the first place. Papyrus was a grown up of course, but he was still Sans’ younger brother and he didn't want his only family to worry about stupid stuff like being able to afford things. He wanted all of Papyrus’ dreams to come true. If he had to work himself down to the bone to make that happen, then so be it. He could take it. 

...probably. 

“WHAT ABOUT IT?” Papyrus asked. “I KNOW YOU'RE ALREADY SAVING FOR IT ON TOP OF EVERYTHING ELSE YOU PAY FOR! SO EVEN IF WE ADJUST YOUR WORK SCHEDULE, WITH MY ADDED INCOME WE SHOULD HAVE MORE THAN ENOUGH TO CONTINUE SAVING. I CAN EVEN USE MY OWN MONEY FOR IT AND YOU CAN USE YOURS TO SAVE UP FOR SOMETHING YOU WANT!”

Papyrus looked rather excited at the idea. But more importantly there was something almost pleading to his demeanour, which told Sans that Papyrus wasn't finished making his case yet. His brother had one final trump card yet to play. Sans didn't have to wait long to hear it. 

“SANS YOU HAVE ALREADY DONE SO MUCH FOR ME,” Papyrus said. And then he got _really_ unfair. “You’re my brother and I hate that you give me all these things and I can’t give you anything back. So won't you please let me do something for you now?”

The quiet voice coming out of his brother's mouth shook Sans down to his core. 

“pap…”

“I love you, brother. I want you to be happy, too. And I can see that you're not happy right now. You're tired and stressed. I can help you now! I can do what I love and still help you! So please, let me.”

They both stared at each other in the quiet of the forest, the minutes dragging on and on. Truth to be told, they both should already have started their shifts at least fifteen minutes ago. And Sans was late for his usual visit to the baby as well. But he couldn't dismiss his brother. Not now. 

Sans thought about this long and hard. His brother had made a really good argument, but Sans wanted to make sure that Papyrus didn't leave anything out. He didn't want to agree now only to find out later that he had overseen something important that caused problems for them. No matter how he looked at the issue though, he couldn't find a flaw. His brother did earn the same base salary now as Sans did, and worked three shifts a day. Even if Sans cut back on his own shifts, they would easily make up for the difference, especially if he kept selling hot dogs at his Hotland station. 

They'd have enough money.

He'd have more time for his brother, the baby, _and_ he might get some sleep. 

And if he managed to convince his brother that one of the shifts he dropped was the Waterfall one, he'd also have less trouble with worrying about Undyne discovering him missing or sleeping. 

Sans turned the issue over and over in his head, but he could only see advantages. That actually worried him. What if he was subconsciously overlooking something because he just wanted a break? Make things easier for himself? Sans knew himself. He knew that while he could work hard if necessary, he was ultimately lazy and preferred to take the easy solution. It had bitten him into the tailbone on multiple occasions already and what if this was one of them?

Papyrus waited for him to make a decision looking at him expectantly. 

Sans really appreciated that his brother didn't push him while he was thinking. He knew that his brother really wanted this for him. But he wouldn’t force Sans. He'd respect whatever decision Sans would make even if he didn't like it. 

Despite everything, Sans felt tempted to decline. To keep working, pretend that nothing was wrong, use the money they both earned together to build up their savings and buy things that would make his brother happy. But rationally, Sans had already known for a while that he couldn't keep going like this. He'd needed to for the time being, but he had no idea when he'd break down over the strain. Now that the opportunity to improve things was offered to him on a silver platter… yeah, he only had one answer to give. 

“ok,” he said quietly, looking down at his feet. Agreeing somehow felt both relieving and like a failure on his part. He really hoped he was making the right decision. “do i get to have say which shifts?”

“OF COURSE, BROTHER!” Papyrus exclaimed happily, practically sagging with relief aver Sans’ answer himself. That made Sans feel even guiltier. He didn't want to worry Paps so much. “WE CAN LOOK OVER YOUR SCHEDULE TOGETHER AND DECIDE, ALTHOUGH OF COURSE WE HAVE TO TAKE THE OTHER ROTATIONS INTO CONSIDERATION.” 

“ok,” Sans said again, glancing up at his brother. “cause i don't wanna leave you alone here.”

He would insist on that. 

If Sans was gone, Papyrus would be the first in line should another human fall. He’d essentially take over Sans’ position and become the one to man the first alert station all by himself. And unlike Sans, Papyrus couldn’t take shortcuts, would have to rely entirely on his own strength and speed to escape the human if it should turn out to be too strong for him to handle. That was completely unacceptable.

There was no way in hell Sans would allow this, especially not after the massacre he had witnessed in the ruins. 

“NO WAY, HOW WILL I KEEP SUPERVISING YOU IF YOU DON'T WORK WITH ME? WINK!”

Sans began to chuckle at Papyrus’ obvious display of making things work in his own favour. His brother may claim that he wanted to earn Undyne’s trust and Sans had little doubt that was true, but Papyrus was obviously not above a little meddling at least. And his proposal to change Sans’ shifts was surely something he'd discussed with Undyne as well, putting his arguments to good use in order to convince her that this wasn't just the best for Sans, but also wouldn't cause trouble for the rest of the guard. 

His bro was just the best. 

Sans tugged at Papyrus’ arm until his brother crouched down so Sans could give him a proper hug. He wasn't usually the most emotional guy and he didn't want to cry his eyes out or anything, but… he did feel very grateful and happy right now. Knowing that his brother cared so much, cared enough to not just make the proposal for Sans to work less but to actually take all the issues that could come with it into consideration, to make sure that he could soothe Sans’ worries with facts instead of nice words. To know that his brother respected Sans’ worries and opinions. To know that Papyrus, in spite of everything, would have let Sans continue out of respect for his decisions. To know that Papyrus didn't try to manipulate him but instead presented his argument in an honest and open way so Sans could think about it and make his own decision. All of that made Sans feel deeply loved and appreciated.

“thanks, paps,” he mumbled, wishing he knew better how to put his feelings into words. 

“NYEH HEH HEH! THERE IS NO NEED TO THANK ME, BROTHER!” Papyrus squeezed Sans close and only let go once Sans stepped back. 

“welp. guess we should go to work,” he said as casually as possible. 

“YES WE SHOULD! WHILE THIS WAS AN IMPORTANT CONVERSATION, WE SHOULDN'T BE LATE MORE THAN NECESSARY!” Papyrus agreed, glancing over to his sentry station with obvious pride. He really took his new dream job very seriously. 

“ok. i’ll see ya later.”

With a wave to his brother, Sans walked on through the forest. As soon as he was able to turn a corner so he was out of his brother's sight, he took a shortcut to the ruins. 

The baby waited for him sitting upright, flinching in surprise when he popped into existences right in front of them. For a second he was worried he had startled them into crying, but then they suddenly started giggling instead, clapping their hands in joy. That was a relief, he hated when he had to spend too much of their already short time together with calming them down.

“hey there,” he said calmly, lowering himself down to pick them up. “you had a nice nap while i was gone or were you awake the whole time? probably the latter, heh.”

“Adadadada!” made the baby. 

“thought so. you still green on the poop front? no giant fart coming?”

“Da!” the baby said enthusiastically. 

Sans felt their bottom just to make sure and rocked them a little. It seemed like they were fine though. He had already given them the usual treatment of cleaning and feeding them before his brother came to ‘wake him up’, and that hadn't been too long ago. Still, sometimes they pooped again in that short period of time. And he hadn’t had the time this morning to make sure they got all the gas out of their body, so he decided to take care of that now. 

He gently laid them back down on the blankets that covered the floor and began moving their legs back and forth. Rocking them worked too, but that could also make them throw up as he had found out in a rather disgusting trial-and-error process. Not a memory he particularly liked to relive. This method, where he rhythmically moved their legs against their belly, worked better and seemed to be easier on their stomach. He had discovered randomly that it was a good way to make them fart when he had been joking around with them and suddenly ended up with a couple of choice toots hitting the air. 

“heh,” he chuckled when they proved that their ‘Legendary Fartmaster’ nickname was still entirely accurate. “nice one, kiddo.”

They kept beaming up at him, showcasing the two small teeth that had sprouted from their lower jaw just a few days ago, right in the centre. He was relieved that they didn’t have that bothering them anymore, but he didn’t fool himself thinking that their crankiness over growing teeth would be over now. Humans had more than two teeth after all, and the others still had to come out. He didn't even know how many humans had, or how long it took for them all to grow out. Fun times ahead. 

For now though, they seemed happy and content, which eased the stress and anxiety in his soul somewhat. 

“there ya go, happy as a clam,” he declared when it seemed that they were as gas-free as they would get. 

“Dada!” they squealed. 

“...still insisting on that, huh?” 

“Dada!!!”

He scratched the back of his skull, his soul squeezing hard in his chest. 

Dammit. 

Sans would have liked to keep pushing that thought away from him, but who was he even fooling anymore. He was their sole caregiver, protected them from the murderous intent of the other monsters not solely because of his promise anymore, and found himself increasingly fond of their squishy little face. 

No matter how much he had wanted to resist taking responsibility for them in the first place, or to resist liking them, a father was basically what he had become for them. 

Still, the thought made him uncomfortable. 

He had raised Papyrus to the best of his abilities when it had become necessary, and that was honestly enough for a lifetime. Not that he resented it or anything. He loved his little brother more than anything else in the world and having stepped up was something he’d always do again, no questions asked. Hell, he was damn proud of how Papyrus turned out. His brother was a good monster. Kind, strong, clever, motivated, successful. He had so much going for him. Papyrus was simply the best and knowing that he may have had even a small influence in shaping the person his brother ended up becoming filled Sans with vast amounts of pride and awe and love. 

But… there was also no denying that it had been a tall order. 

Papyrus had been loud and boisterous and demanding even as a little kid and looking after him had taken a lot out of Sans. He had decided early on that he’d had his share of fatherhood, and that he didn’t want to have kids of his own in case he ever got into a relationship with another monster. Not that that was likely to happen given his own lack of motivation in that regard, but just in case. And if Papyrus ever had kids, Sans would be more than happy to be around as a chill, supportive, slightly weird uncle. The one who’d take the kids to the science exhibitions in New Home and buy them dumb shit as a birthday present. 

And now, that was suddenly all tossed out of the window. 

He didn’t have a choice anymore. 

No matter what he called it, it was clear what kind of role he was fulfilling for this kid.

“c’mere, ya little gremlin,” he sighed and picked them up again, cradling them close. They had already been looking at him expectantly and he didn’t have much time left before he had to return to his station. They needed the attention and affection so he’d better cuddle them a bit before he left them alone again. 

“Dada,” they insisted stubbornly, grabbing at the strings of his hoodie and looking up at him. 

“you're pretty insistent for someone so small,” he replied. He reached over and stroked the tips of his phalanges over their cheek. Their skin was very soft but also very sensitive, and he had recently started to bring home lotion to apply to them for after their baths. They would sometimes get red spots if he didn't. 

“Da,” they replied seriously. 

“not a bad thing necessarily,” he continued, pretending to have a proper conversation with them. “just sayin’. it's a thing with you.”

“Dada!” they replied, more insistently again. They kept giving him this very expectant look. Sans knew that they likely still didn't understand how words and meaning related to each other. If he didn't react to the name dada, they may just stop saying it in time. They would never know that there was a potential connection there, or if they did find out it would be much later when he could talk to them and explain his reservations about the title. All he had to do was wait and be patient and it would pass. Even if he acknowledged his role to himself, he didn't have to do so out loud. He didn't have to teach them to call him that. It could, at least out loud, stay nothing more than a commitment undertaken because of a promise made to his dead friend. 

_Her_ journal was in his hoodie pocket, pressing against his side as if he was prodded to make a decision. 

The baby stared at him now that he wasn't replying, their brown eyes practically boring into his eye lights. Sans sighed.

“Dada?”

“...yeah.” 

They giggled.


	8. Make a Promise

**Notes for the Chapter:**

> Quick notice: Since the holidays are imminent and I'll probably be busy with stuff, probably struggling to keep up my wordcount at all, it's possible that the next chapter of this fic will be delayed. I'll try to get it out on time! But no promises. I hope you understand, and happy holidays!

“damn. this is the life,” Sans sighed. 

“Da,” the baby said, which Sans decided to take as agreement. 

“should've let him do that sooner,” he added. 

“Adadada,” the baby said seriously. 

Sans hummed, slowly but surely feeling too tired to speak properly. The baby hummed back, which made him chuckle. The baby giggled in return. Soon he and they were full out laughing for no real reason at all. It took both of them a while to calm down. 

The laughing felt good and in the aftermath, Sans felt even more relaxed and loose-limbed. He could feel the baby reaching a similar state of relaxation, getting more and more floppy where it was lying on his upper body. He had fed and cleaned them already, they had played a bit, and now he still had time to take a nap with them. 

This was the best. 

Papyrus and he had looked over his schedule together and just like Sans wanted, he dropped his Waterfall shift to give him the second part of the morning off. On Papyrus’ insistence, he also ended up shortening his afternoon shift in Hotland by two hours. And Papyrus himself also told Sans that he was to use those breaks for nothing else but to rest up, to fix his sleep problem.

Sans decided to head to his room and then port over to the ruins from there, where he spent time with the baby and took naps together with them. With more time, he was able to take much better care of them and still find time to rest.

It was nice.

It was so nice that he was almost scared to trust his good luck, but he didn't want to go down that line of thinking now. The baby was curled up on top of his rib cage breathing deeply as it slid into sleep, and Sans himself felt calm and at peace for the first time in a long while. He had the alarm on his cellphone set and the volume of his ringtone cranked up in case Papyrus called. So even if he fell asleep now, he should be able to wake up in time so his brother wouldn't have to worry. 

This was good. Things were good, he was doing well. I'm doing it, he thought to himself, not reaching to touch _her_ journal but directing his thoughts at it. He wondered if _she'd_ be proud of him. If he was doing well enough to earn _her_ praise. He knew _she'd_ be able to do better of course, just based on the knowledge accumulated in the house about humans and human children. But he still liked to imagine that _she_ would praise him and tell him _she_ was proud of him. 

It was a nice thought. A nice daydream to fall asleep to. 

He allowed his eye sockets to close, enjoying how quiet it was here, the warmth of the baby on top of him, the sounds of their breaths and his intermingling. He drifted into sleep easily and quickly, without any other dark thoughts to weigh him down. 

When he woke up to his alarm, he felt surprisingly well rested all things considered. He hated waking up to that shrill tone, but he got so little sleep ever since he started taking care of the baby that every bit he got now was a blessing and felt amazing. He also felt somewhat less weighed down recently. 

“ok,” he said sleepily. “time to get up.”

It was only then that he noticed that the baby wasn't lying on top of him anymore. 

Oh no. 

Sans sat up so quickly that he felt dizzy for a moment. His brief moment of shock thankfully passed quickly when he saw the baby across from him at the wall. 

“man, don't crawl away from me and scare me like that,” he chuckled. 

“Adada! Da!” the baby told him seriously, without looking at him. 

Sans was about to move over when the baby leaned their weight against the wall, brought their legs underneath themselves and attempted to stand up, only to topple over immediately and hit their head on the wall. 

“shit.” 

He practically flew over, but he still didn't get there in time to prevent their surprised expression from transforming into one of deepest unhappiness and stop them from crying. It was thankfully not the shrill and piercing shrieks they produced when they were hungry and had soiled themselves, but they were still crying loudly. They made a pout when he was next to them and raised their arms up to him. 

“shh, it's okay, let me see,” he soothed them, picking them up and taking a closer look at the forehead where they bumped it. It didn't look bad, there wasn't even a red spot visible. When he felt their forehead with his phalanges, he couldn't feel a bump either, so they probably didn't hurt themselves too badly. 

“see, it's okay. nothing bad happened. you're okay.”

The baby sniffed and he carefully muzzled them, dragging his nasal bone over the soft skin that covered their own bone. He rocked them a bit and made shushing noises and gentle mumbles. After only a few moments, they had calmed down again. They still looked at him with a pout and clung to him tightly though. 

“so, you're trying to walk now, huh?” Sans asked with a sigh. 

Of course. Just when he thought one crisis was averted, the next one reared its head. He didn't really have enough emotional capacity anymore to feel upset about it. It was just the way things were now. 

“Bwuuh,” said the baby, it's pout even bigger now. They extended their finger and reached for his teeth, poking against the flexible ridge that surrounded his rigid denture. 

“arrrh,” he made, pretending to bite them without actually putting any pressure on their tiny fragile adorable finger. 

They giggled in response. 

“there you go,” Sans smiled. “look, sweetie, i gotta go back to work now, i’m running late if i stay any later. but i’ll come back soon, ok?”

The baby looked up at him with betrayal in their eyes when he moved to put them down and began crying again. They immediately reached for him again and tried to cling to his hoodie. 

“kiddo, please. i can't stay. i thought you knew this already,” he tried to argue. Of course it was useless. The baby was still at a very simple level of speech, having figured out that he might reply if they called him dada, and react if they pointed at something and shouted a single syllable while doing so. He couldn't explain to them why he had to leave. 

But honestly, they had never reacted like this when he tried to leave the ruins before. What now?

“come on,” he prompted, tugging gently at their hands where they clutched his hoodie in their fists. They cried harder and he stopped. Well this wasn't working. He decided to try a different approach. Sitting down on the floor, he allowed them to stay close to him and grabbed the bunny plushie instead, which had become a favourite of them after he had used it evening after evening to tell the story of fluffy bunny to them. “look, fluffy bunny is here to watch out for you.”

They grabbed the plushie and leaned against his torso, soothed by his presence and their favourite toy. 

He felt guilty, but it had to be done. 

With their attention distracted, he quickly put them down and took a shortcut back into his room. 

“sorry kid,” he mumbled quietly, feeling like the lowest scum possible. They just wanted to be close to him and he had to trick them to leave them behind. So much for doing well. He was the worst. 

Maybe he could make this up to them, he thought while he left his room and went down into the kitchen. Papyrus wasn't there. He decided to accompany Sans to Grillby’s for a milkshake today and apparently already went ahead. Sans took another quick shortcut to the front of the bar and went inside, being greeted by the regulars like he usually was. Papyrus was indeed at the counter and chatting with Grillby. 

For the next half hour, Sans had a great time with his brother and his favourite barkeeper. He made a lot of jokes, Papyrus pretended to hate them, the whole bar laughed, Grillby’s fire was as calm and unflappable as always but the little flicker of sparks going off every now and then betrayed his good mood.

Sans still had the baby on the back of his mind of course. Would they try to walk again? What was he supposed to do now that they attempted it? Were they still crying or would they have calmed down by now? And how could he soothe them better next time? They didn't understand his actions or motivations without a way to communicate and from what little information he had been able to find in the books, it would still take them months or years until they could understand and talk to him. 

He'd take a cup of milk back today for sure, and since they had two teeth now… maybe something sweet? Something soft of course. A donut perhaps; it was easy to chew and could be softened further by their saliva. He wouldn't give them the whole treat of course, that would be too much for their little body. He didn't want to overfeed them on sweet stuff, that probably wasn't healthy. Paps kept saying so at least, and so did the books on human nutrition, even if those weren't for babies. But a little bit as an apology, that would work. 

Decision made, he took another shortcut at the end of his break once he had said his goodbyes and left his brother. He had to go to Hotland for his next shift anyway, so going to Muffet's wasn't much of a detour. The single donut was so expensive that he felt guilty all over again, at least until he remembered that he and his brother both had an income now and that Papyrus had gotten positively indignant when Sans wanted to keep saving for Paps’ car regardless. It was _Sans’_ money, Papyrus insisted, and he should do something for himself with it. It still felt weird to Sans though. What on earth did he have to buy for himself? There were so many things that were more important. Like Paps, and now the baby. Muffet seemed surprised at his purchase, but didn't question him further. Sans made his way to his station, set everything up for his shift and his under the table hot dog business, waited five minutes, and then returned to the ruins when nobody passed by. 

Back in the baby's room, it was suspiciously quiet. 

At least for the first moment. 

As soon as he spotted the baby and they spotted him, they let out a piercing wail, crawled over to him, and reached up for him with their arms. 

“yeah. i know. i deserve this. c’mere,” he said and picked them up, holding them close to him and giving them a nuzzle. Or at least he tried, because they immediately reached around his neck with their arms, hugging him back as much as they could. Then they wept into the crook of his neck, spreading moisture on his bones and hoodie. 

He had expected them to be upset when he returned, but he didn't think they'd be this clingy. They never had been before. 

“i’m sorry,” he repeated. He rocked them a little, feeling helpless in the face of their bitter tears. They had cried before, a lot, and he was used to not being able to calm them down quickly. But they sounded and acted so different now. This wasn't quite the kind of crying where they whipped themselves up into a frenzy until they seemed to be screaming for the sake of screaming, getting hoarse and yet keeping it up. The way they were crying now reminded him more of how Papyrus had cried when he was small, when he had felt lonely or as if Sans wasn't paying enough attention to him. 

Well.

He did the only thing he knew and kept hugging them, rocking them and mumbling soothing words in a low voice. Apologies and cute nicknames that he pulled from who knew where, observations from his time away and more apologies and promises that it was all okay now and he would make it better. 

Eventually they calmed down enough to resurface from where they had hidden their face in the crook of his neck, although they still didn't let go of him. Their face was red and covered in sticky residue from their tears. They were pouting and refused to look him in the face, instead fixing their eyes on his shirt as they kept snuffling quietly. 

“i feel like scum,” he told them, producing a tissue for them to blow their nose into. That was something he had only taught them recently, but it was useful since they could produce a lot of nose slime. It seemed that they could produce some sort of gross liquid from almost every orifice they had and it was good to be prepared for that at any moment. They blew their nose into the tissue when he pinched their nose and let go again. He decided to pop over to the kitchen to discard the tissue and also so he could get started on warming up some food for them. He'd give them the donut, but they should have a bit of proper food first. 

“how about carrot and sweet potato puree? your favourite,” he told them. The baby kept clinging to him, as if wary that he might let go of them at any second. He was tempted to, truth be told, but he knew it would be a bad idea. So he managed despite the difficulty of warming up food with only one hand. 

They accepted the puree without trouble, eating quietly and obediently. At other times, Sans would have been thrilled to see them so quiet and calm during feeding time. But now it upset him. It was unlike them to be this silent. 

“okay, this is my secret weapon,” he told them once they had finished eating and he had put the spoon he used to feed them away. He'd take care of the rest later. He reached into his inventory and produced the donut, tearing a small part off and holding it in front of the baby. “here ya go.”

They looked at the treat skeptically before they finally moved their eyes up to regard him with just as much skepticism. 

“yeah, it's food. for you,” he explained. He took a bite of the donut himself and chewed thoroughly. The donut was almost too sweet even for his tastes, but it still tasted good. He held out the piece for them again and they finally opened their mouth and allowed him to put the treat inside. 

They weren't quite able to chew yet with their two lone teeth; instead they kind of salivated it into their desired softness and used their teeth to work through the resulting pulp before they swallowed. 

Watching their face transform from miserable pouting into surprised happiness was a treat all in itself.

“good?” he asked with a growing grin.

“Mmmmmh!” made the baby. 

“heh. thought so. more?” He offered them another small piece, which they readily accepted, now awaiting him with their mouth wide open and their eyes as big as he ever saw them. 

“Mmh, mmh mmmh,” they made, shaking their tiny fists in excitement. 

“you happy again, hmm?” he asked them softly, his voice low and gentle now. 

“Dada?” they asked after they swallowed, looking up at him. 

“yeah,” he confirmed, leaning forwards to see if they would let him nuzzle them. They allowed it now, leaning in too and they even moved their head sideways so their skin and his nasal bone touched and rubbed against each other softly. 

“Da,” they said decisively, patting the palm of their chubby hand against his zygomatic arch. “Adada baba da ba!”

“i agree, i’m a terrible father. i try, you know?” He tried to look sufficiently chastened while saying this. 

“Dababa,” they decided. 

“yeah. you got it difficult too. not saying you don't. we both gotta try our best, you know? gotta do this together, you ‘n me. we won't make it if we don't work together,” he explained. It was useless since they didn't understand him, but it still made him feel better. 

“Badada,” they said, using a clearly chiding tone of voice. For someone who couldn't use language properly yet, they sure were good at imitating the way he spoke sometimes. 

“no, i won't trick you anymore,” he promised. “well. i’ll try not to? but you gotta stop clinging to me like that too, you know? i have to leave sometimes, i can't help that. you know how it is.”

“Ba,” the baby mumbled, poking their fingers at his teeth. 

He sighed, and pretended to bite them again, making them giggle. 

“c’mon, i gotta go back to my station,” he told them, slowly carrying them back to their room. Not through a shortcut, but on foot so he could rock them and cuddle them on the way there. He entered their room and closed the door behind himself, walking to the middle of the room before sitting down. “here we go.”

The baby looked around and let out a small wail, clearly understanding what was about to happen. They looked up to him again in what he would swear was a pleading manner. 

“sorry, sweetheart.”

Their unhappy crying seed to pierce his soul when he set them down and took a shortcut to his sentry station again. The rest of the afternoon passed in a similar manner, brief moments of happiness that turned sour when the baby started crying as soon as he had to leave, trying to cling to him. His afternoon break where he could take a nap together with them was the only time when they were happy together for a longer amount of time. But of course the resulting separation was only worse afterwards. When he returned to his own room after finally managing to get them off him, he felt tired in spite of his good nap. He felt emotionally drained and out of his depth. 

And then of course their sudden clinginess was only half of the problem. He also hadn't forgotten that they had tried to stand for the first time today. This produced a whole row of new problems. He couldn't delay it, they would walk in the near future. And the room they were in now wouldn't be big enough for them for long. But he couldn't leave them roam in the house all by themselves either, he already felt worried leaving them alone in the room, even though he did his best to make it safe for them. 

So it was a question of both safety and social interaction. They were lonely and they needed more possibilities to explore and move, but he couldn't provide this for them all by himself on a frequent enough basis. He was too limited by his job and his other obligations to his brother. 

But what was he supposed to do?

Get help after all?

By whom? 

He couldn't think of a single monster who would willingly raise and protect a human baby at the expense of the monster's freedom. They were so close to being free, only one soul missing. And the last soul would be so tantalisingly easy to gather. The baby was helpless, couldn't harm another monster even if it tried. And it couldn't even try. How many monsters would think that a quick bullet would be the best solution? Just one well placed shot and it would be over. The baby was so fragile, so small, so helpless. A hard hit on the thin bones of their skull, a sharpened attack driven into the vulnerable flesh between their tiny, tiny ribs. How many monsters would feel guilty over something that would be killed so quickly and effortlessly, when the result would be the last soul? Freedom for the whole species? Fresh air and the vast sky and the sun and the stars and everything they lost a thousand years ago when the humans banished them. Humans, like the baby he was protecting. 

He couldn't envision it. 

Even Grillby, his calm and reasonable friend, kind and helpful and generally a positive presence in Snowdin, may just decide that it would be better for everyone involved if he let his fire burn just a little bit too hot if he was left alone with the baby. 

Who else? Undyne was murderous. Asgore might feel regret over the humans he killed so far, but not enough to stop. Muffet was generally more interested in profit than anything else… so perhaps if he paid her? But no, she'd know that the king would pay an even higher price if she'd sell the baby on to him. Her spiders came first and for that she needed money. She wasn't a bad monster per say, but she had priorities that could make her ruthless. Alphys was out of the question, she'd be too nervous to keep the secret from her crush and her king, she was already struggling with her anxiety, and besides she wanted to leave even more badly than other monsters since she was such a fan of human entertainment and technology. 

He mentally went through every single monster he knew personally and a few he only knew in passing, but the result stayed the same. He didn't trust them enough to ask them for help.

Perhaps if he had been faster… if he had asked Papyrus before Undyne made him a guard, then perhaps it might have worked. Perhaps then his priorities would have shifted enough that even Undyne’s promotion couldn't have swayed Paps anymore. 

That was wishful thinking of course. It was too late for that. 

He wished he could have told Papyrus. 

He was so tired.

Sans sighed deeply and plastered his usual grin onto his face before he opened the door and walked down the stairs to join his brother for dinner. 

“what’s up, pap?” he said as he ambled into the kitchen. 

“SANS! I HOPE YOUR NAP WAS SATISFACTORY? IF NOT, BE PREPARED TO BE ENERGISED BY A NEW RECIPE BY YOUR BROTHER, THE GREAT PAPYRUS, SPAGHETTORE EXTRAORDINAIRE!” Papyrus waved his spoon where he stood at the stove, spattering tomato sauce across the room which Sans easily dodged with years of practise. 

“i slept well, but that still sounds good, bro,” he said easily, even though he felt more apprehensive than anything else at the moment. Papyrus’ new recipes were more often than not difficult to swallow, and tonight after all the emotional upheaval Sans didn't really feel up for it. He longed for the comfortable, greasy food of Grillby’s, or perhaps just one of the spaghetti batches that Papyrus had cooked to the point of it being mush, but he didn't want to hurt his brother's feelings. 

“OF COURSE IT DOES! MY TRAINING MAY HAVE EXPANDED AND I MAY BE A GUARD NOW,” Papyrus said with an air of importance that still hadn't faded after weeks of his promotion, “BUT UNDYNE STILL CARRIES ON MY SPAGHETTI TRAINING AS AN IMPORTANT WAY OF BUILDING OUR COOPERATION SKILLS!”

It was a fancy way of saying that they were too close to stop hanging out and being silly together. Sans didn't question it of course. They might be overly wild together, but he was happy that they got along so well regardless. Undyne was intense, sure, maybe too intense for Sans personally. And sure, he didn't agree with her on many things, such as the whole killing humans thing and putting so much effort into everything and being loud and high intensity cooking. But he still knew that she was a good monster at the core. She was the way she was, and she cared. Deep in her soul, she was kind and could be surprisingly soft towards monsters others would avoid, such as his brother. For that, he would always like her. Even if he was mad at her for unknowingly causing so many of his issues in regards to the baby right now. 

“sure. how'd your day go?” he decided to ask before he became too distracted by his thoughts about Undyne and the baby. 

“VERY WELL, THANK YOU! LESSER DOG HELPED ME TEST ONE OF MY PUZZLES TODAY IN EXCHANGE FOR A BONE ATTACK AND TOGETHER WE IMPROVED THE PUZZLE’S EFFECTIVENESS BY AT LEAST 50%! THEN LESSER DOG WAS SO HAPPY ABOUT THE BONE THAT I THREW IN SOME HEAD PATS TOO AND I THINK THAT WAS A VERY GOOD DECISION BASED ON THE RATE OF TAIL WAGGING.” Papyrus smiled widely while he squashed onions and something Sans couldn't for the life of him identify into mush. “I THINK IT BROUGHT US CLOSER TOGETHER AS GUARD COLLEAGUES!” 

“heh, nice,” he said and genuinely meant it. “i keep telling ya the dogs are great if ya approach them right.”

“INDEED! ALTHOUGH I STILL DON'T LIKE THAT INFERNAL CANINE THAT BREAKS INTO OUR HOUSE AND TRIES TO STEAL MY ATTACKS AND ESTABLISH ITSELF UNDERNEATH THE SINK!”

“aw. i think it's cute.”

“DON'T ENCOURAGE IT!” 

“i swear ‘m not.”

“GOOD. IN THAT CASE, HOW WAS YOUR DAY? DID YOU SEE ANYTHING INTERESTING AT YOUR STATIONS?” It was pretty clear what his brother was hoping for here. 

“nope, sorry. did see a vulkin gobble up a hotdog with its head crater though. looked funny.” He chuckled at the memory, even though his brother groaned. 

“I DON'T KNOW WHY MONSTERS EVEN BUY THOSE TERRIBLE SAUSAGES. THEY'RE NOT EVEN REALLY SAUSAGES!” Papyrus complained. 

“they're water sausages and all our other sausages are different plants as well so who cares,” Sans shrugged. 

“I SUPPOSE, BUT THERE'S STILL A DIFFERENCE,” Papyrus insisted. Then he sighed. “AND HERE I KEEP HOPING A HUMAN WILL FALL SO WE CAN CAPTURE IT. BUT NO. EVERYTHING IS ONLY ABOUT SAUSAGES.”

“such is life, bro.” 

“DO YOU THINK IT WILL TAKE LONG THOUGH? UNDYNE SAID THE LAST ONE WAS ALMOST A HUNDRED YEARS AGO AND IT HAS NEVER BEEN MORE THAN A HUNDRED YEARS BETWEEN THEM EVER SINCE THE FIRST ONE FELL!”

“dunno, don't think they have a schedule or anything,” he mumbled, not liking that Papyrus insisted on the topic like this. 

“WELL THAT IS VERY INCONSIDERATE OF THEM! HOW AM I SUPPOSED TO CAPTURE A HUMAN IF THEY DON’T FALL ON TIME?” 

“dunno.”

“SANS! THIS IS A SERIOUS MATTER! CEASE YOUR MUMBLING AND FOCUS!” 

“ok.”

“I MEAN IT! IF A HUMAN DOESN'T FALL SOON THEN I WILL NOT BE ABLE TO GATHER THEIR SOUL AND WE WILL STAY IN THE UNDERGROUND! MONSTERS WILL BE UNHAPPY AND I WILL NEVER BE THE HERO BATHING IN THE LOVE OF THE PEOPLE!” Papyrus complained. 

“yeah.”

“I SIMPLY WANT TO HELP PEOPLE AND BECOME OUTRAGEOUSLY POPULAR IN THE PROCESS! IS THAT SO WRONG?”

“nah.”

“DO YOU THINK THEY WOULD MAKE A STATUE OF ME IF I DID IT?”

“dunno.”

“SANS I THOUGHT YOU SLEPT WELL, WHAT IS WRONG?”

“nothin’.”

“BROTHER PLEASE DON'T LIE! IS IT BECAUSE YOU ARE SECRETLY JEALOUS OF MY GENIUS PLAN? DON'T BE! MONSTERS ALREADY LIKE YOU A LOT!”

“nah. ‘s fine.”

“SANS!” Papyrus took his pot from the stove and put it aside before he kneeled down in front of Sans and looked at him with worry. “IF YOU FEEL BAD PLEASE DON'T THINK YOU CAN'T TELL ME! ARE YOU SAD TOO BECAUSE NO HUMAN HAS FALLEN? I'M SURE THAT SOON IT WILL HAPPEN AND THEN I'LL CAPTURE - “

“papyrus, please, you have no fucking idea what you're talking about.”

The sentence was out before Sans could stop to think about it. Harsher than he would usually speak to his brother, laced with fatigue and sadness and fear. They stared at each other in shock, neither of them sure what to do now. 

There were certain things that simply didn't change between them. 

Mostly Papyrus was loud, Sans was quiet. Papyrus was energetic and Sans was lazy. Sans joked around, Papyrus pretended to hate it. Papyrus took care if the housework, Sans pretended to create more messes but kept them carefully controlled so as to not actually inconvenience his brother. 

Papyrus never gave up. 

And Sans always supported his brother. 

That was simply how it worked, The Way Things Were, period, in capital letters and engraved into the foundation of their lives. 

“i’m sorr - “ Sans attempted

“Sans. What is _wrong_?” 

This was the second time already where Papyrus had lowered his voice to indicate how serious he was since this whole mess with the baby started. Sans had no idea what to say. The excuse of being tired probably wouldn't work again, would it?

“pap, it's… you'd have to _kill_ , or you'd have to help someone else do it. do you really think undyne would stop just because you say so? do you think all the other monsters would?”

It was skirting around the core if the problem and Sans could see that Papyrus noticed. 

“WELL, PERHAPS NOT IMMEDIATELY! BUT I'M SURE IF I TRIED HARD ENOUGH I COULD - “

“the human would die,” Sans intervened, a note of finality in his voice. 

“M-MAYBE IT WOULD BE A BAD HUMAN…”

Papyrus’ words petered out, whether it was because he noticed that Sans had started talking about a definite, specific human or whether it was the weary expression on Sans’ face. 

He still felt scared and wasn't sure if it was a good idea. It was difficult. He was so scared that something go wrong. He didn't know how this would go, not after everything that had happened. 

But he was also absolutely sure that things couldn't go on like this. 

Sans took a deep breath and forced the words out. 

“paps. i gotta show you something. c’mon.”

He stood up and extended his hand. Papyrus eyed him with utter shock, but after a moment, he caught himself and his expression settled into something steady and determined. 

Papyrus took Sans’ hand and together they slipped into a shortcut.


	9. Papa

**Notes for the Chapter:**

> The holidays are over so it's time for more fanfic! I hope you all had a good time and a great start into the new year :3 I'm really excited to publish this chapter, I love how it turned out! Hope you like it too~
> 
> [Fanart tag](https://rehlia.tumblr.com/tagged/tbaab-fanart)

They arrived in the middle of the baby's room together. The baby initially smiled upon seeing Sans but then startled badly when they saw Papyrus and began to cry. 

Paying no attention to his brother's utterly befuddled face for now, Sans walked over and picked the baby up, cradling it close and making soothing noises. 

“shh, don't cry, sweetie,” he mumbled while giving them a nuzzle. “it’s just your uncle pap. told ya about him, remember?”

“Dada?” the baby asked in an insecure tone. They were clearly still not sure what to make of this situation. Sans slowly turned his head towards Papyrus. His brother was still rooted to the spot where he left him, staring at Sans like he had grown three new heads and announced he wanted to become the next king of monsters. 

“...pap?”

“S-SANS! 

“yeah?”

“IS THAT A HUMAN?!”

“yeah,” Sans confirmed quietly. 

“OH MY!!!”

“yeah.”

“THAT'S! THAT'S…!!!”

Sans braced himself. He trusted his brother. He loved his brother. In spite of all his worries about Papyrus’ position in the royal guard and his desire to impress Undyne with catching a human, and wanting to change her mind about the killing… he would have to keep trusting his brother. Sans had made his decision. It was long past time for him to share this with his brother. To ask for help. He would have to trust that Papyrus would understand, and if not - 

“THAT'S SUCH A TINY HUMAN! IT'S SO CUTE! ARE ALL HUMANS THIS SMALL?! OH WOWIE! IT'S ALMOST AS LOUD AS I AM!”

The baby was indeed howling again, pressing themselves closer to Sans and hiding their face in his shoulder. Their body was curled up in an effort to make themselves smaller. 

“yeah, they're crying,” Sans explained, briefly so overwhelmed by emotions that he didn’t even know what he was feeling. He began rocking them and gently ran his hand over their back, nuzzling their head so they'd know there was no immediate danger. “they haven't seen anyone but me in ages. that’s probably why. they're not used to it anymore.”

“OH NO! FEAR NOT, TINY HUMAN! THE GREAT PAPYRUS WILL NOT HARM YOU!”

Sans looked up at his brother. 

“you won't?” His voice was soft and he felt bad for asking at all, but he had to make _sure_. It was his baby, he promised to protect them, he had to play it safe. 

Even against his own brother.

Even if that made him feel like the lowest form of scum possible.

“OF COURSE NOT!” Papyrus seemed deeply offended by the question. 

“you won't tell anyone? not undyne and not asgore? it has to stay a secret, paps. it has to. no matter what, i promised i’d protect them and taking their soul would kill them even if it was just for a short bit, they’re really fragile and it’s. they're only a baby. couple of months or something. it has to stay a secret. you have to promise.” Sans knew he was babbling, but he couldn't help it. He had thought about this moment so much, turned it over in his mind and wondered how Paps would react, and what Sans might say in return. Now, it all came tumbling out of him all at once. 

Papyrus stared at Sans, scrutinised him in a way that Papyrus rarely did. His brother was perceptive, but looking at people this way was usually what Sans did. 

“How long has this been going on?” Papyrus eventually asked. 

“about… two months now, i think,” Sans said after a moment if thought. And after getting over the surprise of his brother lowering his voice. Again.

“That's why you were so tired.” A statement, not a question, one made with utter certainty and calmness. “That's why you didn't answer your phone. That's why you were gone. You were here.”

How was he supposed to react? It didn’t sound like an accusation, but at the same time, it did. 

“yeah.”

Sans waited for a reaction, but none came. Papyrus seemed to be at a complete loss for words, for once incapable of saying anything at all. He merely stared at Sans and the baby with wide eye sockets. 

The baby was slowly calming down now that there was no more yelling, and lifted their head to look at Papyrus once more. They had a sort of skeptical look on their face, which softened somewhat when they turned back to Sans. 

“Bwa?”

“just uncle paps, like i said,” he mumbled. The baby patted their hand against his skull, near his teeth. He gently pretended to bite them and it helped to make them smile. 

“Dada.”

“I can't believe you became a father!” Papyrus blurted out, almost reaching his usual volume again, but restraining himself. Barely. 

“heh. neither can i,” Sans quipped. It would be funny how the baby had wormed their way into his soul, if it hadn’t caused him so much grief. But that was over now. Wasn’t it? Papyrus wasn’t freaking out about this as much as he could, but. He also hadn’t promised anything. He tried not to show the panic that was rising inside of him. For now they were safe. He had to convince Paps a little, that was all. 

“It's so responsible of you!”

“ouch.”

“Who did you promise to protect them?”

There it was. Sans nearly winced, but he found that his body abandoned the motion all by itself before it even really began. He thought of the journal in his pocket, though he didn't touch it. For now it was enough to know it was there. 

“there was an old lady who used to live here,” Sans explained. 

“Where are we anyway?!” Papyrus interrupted. 

“the ruins,” Sans said. 

“Wowie! Really?! I thought they were abandoned. And closed off.”

“nah. i used the door to practise my knock knock jokes before. one day, someone answered. we exchanged jokes for a while, had a good time… you could say we became friends, even though we never saw each other. then one day, something was off. i asked about it and she asked me. ‘if a human ever comes through these door, protect them, will you not?’ i hate making promises, but someone who likes bad jokes just as much as i do, someone like that has an integrity i couldn't say no to.”

Papyrus was still, apparently completely entranced by the tale Sans was telling. The baby had a similarly enraptured expression, likely due to how he'd tell them a story to entertain them regularly. For one strange moment, Sans felt as if he was reading a story to both his brother and the baby, as if the events he was speaking of were merely another instance of long-ago and far-away. As if they had happened to someone else. 

“so i promised,” he continued. “and then one day, i came to the door and it was open. behind it was the corpse of a human, and next to that was the baby on the floor. i wanted to take their soul at first, had a sharpened bone ready ‘n all…”

Papyrus tried his best, but he couldn't entirely hide the appalled expression on his face. Sans took it in stride. To be honest, he was pretty appalled himself in retrospect. This warm, soft little creature he was hugging close to his chest, so helpless and dependent on him - how could he have thought of killing something so innocent? They were just a little baby. It was also a relief to see Papyrus feel so strongly about this. That meant that he'd be less likely to end up telling anyone, Sans thought. A good sign.

“but then i remembered my promise and i didn't do it. i knew they wouldn't make it if i didn't take care of them so i did my best. the other human, their parent, they had… well. let's say it was pretty dusty when i walked around the ruins.”

Papyrus winced. Sans had tried to be blasé about it, but he could feel how his own expression tightened. He wanted to reach down and into his pocket, to touch _her_ journal. But he was holding the baby and he didn't want to jostle them now that they were calm. 

“The old lady too?” Papyrus eventually asked in a quiet voice. 

“yeah.”

They both stayed quiet for a moment. And then, because Sans felt he had to, no matter how much it pained him and how much it would pain Papyrus. He said it. 

“i found a flower too. it was slashed and broken. it didn't seem like a normal flower. i don't know if that's… “

“Oh.”

Upon seeing Papyrus shocked and saddened expression, Sans hated himself. He shouldn't have said it. Kept quiet. Or at least he should have said something else. Pretended his brother's friend was just on vacation or something. 

“maybe i was wrong. maybe it was just a normal flower after all.”

“What did you do to it?” Papyrus asked, his voice now fully hushed. 

“i dug a grave for the human,” Sans explained. “didn't want to, but i thought it’d be better than leaving them where they were. there was a flower patch where they fell. i put them underneath there. and the other flower on top. flowers to flowers, you know.” 

He didn't mention how he had also thought that the flower and the human were both evil, and how he had felt burying them together was fitting for that reason. The flower, if it had been the one Papyrus meant, was already dead. No need to make Paps feel even worse by explaining that judging by some entries in _her_ journal, the flower likely hadn't been all that nice in the end. 

Papyrus nodded slowly, visibly thinking about it. 

“Can we go there?”

Sans didn't want to, but of course he understood. He had the journal and that had helped. Papyrus had nothing until now. If the flower Sans had found was really Paps’ friend, then visiting would be good, so he could get a sense of closure too. Especially since the flower had no dust to spread on a favoured object. 

“yeah. sure. let me feed the baby first, okay?”

“OH, OF COURSE!” Papyrus looked rather enthusiastic at the prospect of watching this, which made it easy for him to slide back into his usual volume. Sans had known that the quiet talking wouldn't last for very long. The baby flinched and looked up at Sans with a small whine, but didn't start crying this time. Sans rocked them a little walking out of their bedroom, but otherwise didn't react much. He hoped that he could show them that a loud voice was nothing to be concerned about by staying calm. 

“WHAT IS THEIR NAME?” Papyrus asked curiously, looking around the house as he followed his brother through the hallway and living room towards the kitchen. 

“they don't really have one,” Sans shrugged. What should he feed them? He'd given them a good bit of starchy foods recently to soothe them, so maybe it was back to the greens for now. Mashed peas were always a nice option, perhaps he could add small bits of broccoli too. Not too many, or they'd get gassy again. Nobody wanted that. 

“SANS! HOW CAN YOU TAKE CARE OF A BABY AND NOT NAME IT?!”

“dunno. didn't think about it. i’ve just called them baby. or legendary fartmaster.”

He took out the pureed vegetables and began heating them on the stove. He still found it difficult to manage that with just one hand, but he had some experience with it by now. 

“THAT IS NO WAY TO ADDRESS A BABY!”

“heh. just wait until you hear them toot.”

The baby looked at both of them with big, innocently curious eyes that said that they would never ever do such a thing. 

“I REFUSE TO BELIEVE THAT!”

“give it a bit.”

Sans finished heating up the food, took it off the stove, and began feeding the baby spoonfuls of puree after making sure the temperature was okay for them. Papyrus watched him as if he had grown a second head or transformed into a blaster or something. 

“what?” Sans asked. 

“YOU’RE SO… “ Papyrus made a flailing motion with both of his hands, gesturing to all of Sans and the baby where he was standing, holding them, slowly helping the little thing devour unreasonable amounts of green mush. “SO PRACTISED AT THIS! SO CONFIDENT! SO PARENTAL!” 

“i mean, look at them. they’re hard to resist,” Sans argued. The baby swallowed their latest bite of puree, and opened their mouth again, bits of green smeared around their lips. 

“THEY’RE JUST AS GROSS EATING AS YOU ARE,” Papyurs observed dryly. 

“i know, isn’t it great?” 

He grinned down at the baby, genuinely meaning it. So what if their eating habits were gross, they were still cute. Besides, Paps hadn’t seen anything yet. This was nothing against feeding the baby when they were in a mood. Or when they were snotty; they could create some truly great messes when their nose slime dripped down and crusted on their upper lip while he fed them. Not to mention their poop - but he didn’t want to traumatise his brother, so he probably shouldn’t mention that. The goal was to make his brother like the baby, after all. 

“ok, i think that’s enough,” he decided after a bit more. The baby was mostly suckling on the spoon by now, a sure sign that they were done eating. They kept staring at Papyrus, which made it a little difficult to get them into position so he could rock them some more. 

“WHAT ARE YOU DOING NOW?” Papyrus wanted to know. 

“if i don’t move them after feeding them they’ll have gas build up in their belly, ‘n then they get cranky,” he explained. “so i gotta rock them a bit to get it out of their system.”

“WHEN YOU SAY GAS - “ 

The baby let out a first burp. 

“nice one,” Sans commented. 

“OH MY GOD!” 

“that’s just part of being a baby,” Sans insisted, feeling defensive all of a sudden. It wasn’t the baby’s fault that their digestion worked as it did after all. He suddenly felt he was doing a bad job introducing them. How could he make Papyrus see why he cared about this creature so much?

“do you wanna hold them?” he offered after a moment of thinking it over. 

Sans didn’t feel so sure about this, but he only had a limited time to make sure his brother liked the baby well enough to want to keep it safe too, so maybe he had to take drastic measures. Papyrus had indicated that he thought the baby was cute, maybe holding it would help. And if it did something gross, perhaps carrying it would make the association to Sans stronger and cause a protective instinct by association, or something. 

Papyrus looked both intimidated and incredibly excited by the prospect, his hands twitching upwards while his face showed doubt. 

“CAN I? THEY GOT SO SCREACHY WHEN THEY FIRST SAW ME! I DON'T THINK THEY LIKE ME ALL THAT MUCH!”

It wasn't something Papyrus would usually admit, not even quietly and secretly, so hearing him voice his concerns like this was unusual to say the least. Contrary to his usual capabilities Sans couldn't say if that was good or bad. 

“nah, like i said. they haven't seen anyone but me in a long while. they're not used to it anymore, but i think this will be good for them. they need social contact and all that stuff. here, hold ‘em like this…” 

Papyrus almost flailed when Sans approached and began bringing his arms into position. He stopped himself when he seemed to notice that doing so might hit the baby in Sans’ arms, which gave Sans the opportunity to move the baby over fully. 

Both Papyrus and the baby looked at each other with similar expressions of confused surprise, as if they both couldn't believe how they found themselves in this situation. Sans had to repress a hearty laugh; they both looked really funny like this. He still couldn't help the chuckles that escaped past his teeth. 

That seemed to remind the baby that they didn't actually like being in the arms of a stranger, because they began to wail and reach out for Sans with their chubby arms. 

“OH NO! I'M SORRY FOR WHATEVER I MIGHT HAVE DONE WRONG, SMALL HUMAN!”

“aw. c’mere, you gremlin.” He took them back, cuddling them to his ribcage, but he positioned himself so that they could still see Paps. They kept eyeing his brother skeptically even as their crying petered out into a series of small snuffling noises and hiccups. “it’s just paps. uncle papy. think ya can say that yet, huh?”

“Bwwhh.”

“heh. we'll work on it. ok. now that they're fed…” his mood sombered. Once more he regretted having told his brother about the flower, while at the same time knowing it had been the right thing to do. Now he wanted to hesitate and get it over with simultaneously. The latter won out at Papyrus’ expression, indescribably conflicted. “let’s go.”

He offered his hand to his brother and took a shortcut once Papyrus was holding on. They popped into existence a little ways away from the flower patch, which was currently barely illuminated by a very, very faint shaft of light from above, barely visible at all.

It was enough to see though. 

Enough to see that while most of the flowers in the patch had wilted, one was different. 

The colours of the slashed flower Sans had found hadn't faded, standing out clearly against the more muted background. Brilliant yellow and green, with thin gashes of red covering it, although the latter had stopped leaking at least. It still looked gruesome. Sans hadn't expected it to look like this and immediately wished he would have come here alone first, to spare his brother the sight. 

“That's him,” Papyrus whispered. He seemed completely sure and Sans accepted his judgement without question. It had been Paps’ friend after all, so he'd know. 

“i’m sorry, paps,” Sans told his brother in a quiet voice, placing one hand on his shoulder for support. He didn't know what else to say, but perhaps nothing else was necessary. Papyrus placed one of his own hands on top of Sans’ and like this, they remained for a while, both lost in their own thoughts. 

Sans thought about _her_ of course, but he also thought about the other human, the baby's previous caregiver. He was still filled with grief and rage whenever he thought about the massacre they had enacted. But he also felt a small amount of compassion. If he thought someone was trying to hurt the baby now, he'd react badly as well. He wouldn't dust whoever crossed his path, but when he thought about it, imagined himself alone on the surface, surrounded by humans who seemed hostile to him and the kid, in what he could think of as the closest approximation of what the human must have felt like… he liked to think he would have shown more restraint even then, but if he was honest with himself, he wasn't entirely sure. 

It was painful to admit. 

Would he have killed someone like _her_ too? A kindly old woman who tried to offer help, even if she looked scary? 

His soul clenched at the thought and refused to go there. It hurt too much. Sans felt the answer was no in any case. After all, he had found it within him to care for the baby despite his initial feelings. He might understand the human a little better by now, but there was still a difference between them. 

“Ba?”

He was startled out of his thoughts. The baby was holding one of his hoodie strings in their hands, looking up at him and holding the string towards him. Based on their hopeful expression, he suspected they had gotten bored and hoped to play. 

“shh, we'll go and play soon,” he told them quietly. 

“I THINK I'M READY TO GO,” Papyrus announced immediately. 

“you sure?” Sans asked. “we don't have to go yet, i can keep them occupied for a little bit longer if ya want.”

“THAT IS VERY NICE BUT THERE'S NOT MUCH I CAN DO BESIDES...PAY MY RESPECTS, IS THERE?”

Sans looked down, followed his brother's line of sight to the flower patch, a wilted grave for two miserable creatures that, perhaps, hadn't been completely miserable after all. 

“i could go and fetch a shovel,” he offered, “and we could dig a grave for your friend too. a proper one. we could come back and water the flowers so it looks nicer. regularly i mean.”

“I LIKE THAT,” Papyrus said after a moment of thinking about it. “THANK YOU, SANS.”

Sans nodded, and popped back into the house. He remembered where he left the shovel the last time he used it, so it wasn't a big deal to fetch it again now. Since he made the suggestion to water the flowers, he also made a brief detour to the kitchen to fill a container with water.

“Adadada!” the baby suddenly said. “Baba.”

“oh? ya feelin’ like talking again all of a sudden?” Sans looked down at the baby, still clinging to one of his hoodie strings with one hand, while the other was waving around as if it was gesticulating. 

“Bwabababa.” 

“you really don't have to be shy around paps. i think he likes you too,” he insisted, on what he hoped was more than just wishful thinking. 

“Ba.”

“i hope he'll help us, you know,” Sans mused. “just a bit. so it would be cool if you liked him too. just saying.”

“Dada.”

“ok. thanks kiddo.”

He went back through the shortcut, appearing in the same spot he was in before he left. Papyrus hadn't moved from what he could tell, merely kept looking around the cave. 

“I THINK IT SHOULDN'T BE TOO FAR AWAY FROM THE CENTRE,” Papyrus announced as soon as Sans handed him the shovel. “AS A FLOWER HE WOULD SURELY APPRECIATE HAVING A SPOT WITH A CHANCE OF SOME LIGHT!”

“yeah, that's probably true,” Sans agreed. “do you need help digging?” 

“NO, THANK YOU. YOU ALREADY BROUGHT MY FRIEND HERE. I SHOULD BE THE ONE TO DO THE REST. HE TOLD ME I WAS HIS CLOSEST AND MOST IMPORTANT FRIEND. IT’S ONLY RIGHT.” 

Papyrus was wearing an expression of grim focus now, one that Sans didn’t really like all that much on his brother. At the same time, he couldn’t deny that Paps was right. Those closest to a monster should handle their remains after their death - that was how things were done. And even if this flower hadn’t left behind any dust, that didn’t change tradition. Sans might think whatever he wanted of the flower, might even think it had been lying to Paps, but ultimately none of that mattered. If the flower had told Papyrus that he was its closest friend, then his brother had an obligation to fulfill. 

Sans rocked the baby when they began babbling again while Papyrus dug. He felt as if he should be saying something, but when he had had spread the dust of the monsters who died because of the human, he hadn’t said much either and the silence had felt right for the somber atmosphere of the task. So he didn’t say anything either and let his brother decide if he wanted to speak or not. 

It didn’t take Papyrus long to dig out the grave. The flower was a lot smaller than the human Sans had buried had been. Sans was glad that his brother didn’t have to dig for so long, even though Papyrus likely would have been capable of doing it without any trouble. At least not any physical trouble. Once he was done, Papyrus carefully lifted the slashed flower from where Sans had placed it months ago, and laid it down into the small grave. 

“Do I just throw the earth back?” Papyrus asked. 

“it’s what i did with the human.”

Papyrus nodded. He stared at the flower for a bit longer, before he began digging again, this time to cover the flower in earth. Sans just kept rocking the baby, trying to keep them quiet. It was a somber moment, and he wanted Papyrus to be able to say his goodbyes in peace. Thankfully, the baby seemed content for the moment, happy enough that he was holding them and rocking them, petting their head here and there. It was enough for them to stay calm. 

When he was finished, Papyrus stood up. Assuming that his brother would want to be the one to do this too, Sans handed him the container with the water as well, and watched as his brother poured some over the grave of his friend, and the rest over the patch of wilted flowers. 

“We can come back here, you said. Right?” 

“always,” Sans promised, neither willing nor able to deny his brother. Not for this. 

“Good. Then we can go.”

Sans looked at his brother, despising how quiet he was. Of course he understood the necessity to grieve, he had been through the process himself. But he hated seeing Papyrus so quiet and sad and straightforward. He had always tried to keep his brother happy and now he felt like a failure for somehow having allowed this to happen. A part of him insisted that ignorance was bliss, and that he never should have told his brother about this mess after all. The larger part, the part that had spent the majority of the past few months in mourning while simultaneously dealing with the demanding reality of a fussy baby, the part that had to grow up in ways Sans never thought he still had growing up to do - that part insisted he had done the right thing. 

It was done and Papyrus deserved the truth, deserved the chance to properly deal with the loss of his friend. All Sans could do now was to be there for him. 

“...do you wanna take the long way back? there’s puzzles. new ones,” he clarified when his brother looked at him in a questioning way. It was a simple idea to cheer his brother up, Sans knew this, Sans also knew that Papyrus knew this, they both could see it on each other in different ways. 

Still, Papyrus smiled. 

“THAT SOUNDS FUN! LET’S GO!” 

“Ababa!” the baby suddenly yelled. 

“I HAVE NO IDEA WHAT YOU’RE SAYING, BUT I’LL ASSUME YOU AGREE WITH ME! ALWAYS A GOOD CHOICE!” 

Papyrus reached out and gave the baby a pat on the back, which the barely allowed after giving first Paps and then Sans a questioning look. 

“i think they’re getting used to you,” Sans said as he started to walk in the direction of the first puzzle. 

“DO YOU REALLY THINK SO? THEY HAVE THAT SCRUNCHY LOOK ON THEIR FACE STILL. YES, THAT ONE!”

Sans chuckled when he saw that Papyrus was right, and the baby was regarding him with the skeptical look they'd been giving his brother all evening. 

“c’mon, sweetie. it's uncle paps. can you say that, huh?” he asked while Papyrus gleefully looked around the big room with the double staircase to the actual ruins. 

“Buh?” made the baby. 

“paps,” Sans said slowly. “papyrus. paps.”

“Abababababa!”

“not quite. paps. papy.”

“OR THE GREAT PAPYRUS, DON'T FORGET THAT ONE!” Papyrus chimed in.

“that might be a bit long for them,” Sans chuckled.

He followed his brother up the stairs and into the first puzzle room. Papyrus stared at the stone slabs on the floor and then went to inspect the lever on the wall. 

“paaaps,” Sans repeated again, patiently waiting to see if the baby would get it. 

“Bababa!”

“paps,” Sans said once more. He'd keep repeating it for a while, he thought, after all this was new for both of them. He had responded to their babbles until it had become natural for them to address him that way, and he encouraged other babbles and speech development by talking to them whenever he could, treating their sounds like statements he could reply to, so they would learn that language was an exchange. But he hadn't actively tried to teach them a word before. Not like this. He wasn't sure whether they were even able to grasp the idea yet; he had remained unable to find further information about humans at this age and so his knowledge about human language development was sparse at best. 

A click and a following crunch told him that Papyrus had solved the first puzzle. Sans strolled up to his brother, pointing at him while they walked. 

“there, that's him. paps.”

“Baba?” The baby looked up at Papyrus, this time with a smaller amount of skepticism in its eyes. 

“p,” Sans made, stressing the sound to the point of it sounding silly. “p, p. paps.”

“Pppphhhfff,” made the baby, covering Sans and Papyrus in a good bit of baby spit. 

“TINY HUMAN PLEASE STOP ASSAULTING ME WITH YOUR MOUTH SLIME!” Papyrus screeched. 

Sans merely laughed. 

“that's nothing, you don't wanna see their real mouth slime.”

“STOP BEING SO HAPPY ABOUT THIS FACT! YOU SHOULDN'T ENCOURAGE THEM TO PRODUCE SLIME LIKE YOU DO!”

“pfff. they don't exactly need encouragement, paps.”

“BUT - “

“Papa!”

They both paused. Stilled except for a simultaneous movement of their head, to look down at the baby in Sans arms. They looked back up expectantly, their expressions practically demanding praise. 

“DID THEY JUST…?”

“say paps again,” Sans prompted. 

“Papa!”

“SANS DID YOU HEAR THAT!!!”

Papyrus sounded beside him with glee, causing Sans to smile more widely than usual too. 

“sure did, bro.”

“Papa?”

“YES! YES, TINY HUMAN! THAT'S ME!!!” By this point, Papyrus had bright sparkles dancing in his eye sockets, the happiness he felt manifesting through his magic.

“well done, kid,” Sans praised them, giving them a nuzzle that made them giggle. 

“I NEVER BELIEVED I WOULD SO SUDDENLY BE A FATHER AS WELL! WHAT A STRANGE AND YET WONDERFUL FEELING!”

“heh. i know what you mean.”

“Dada papa dada!” the baby yelled, waving their arms around excitedly. 

“YES! LOOK SANS, THEY ARE SO CLEVER!” 

“i know,” Sans said warmly. 

Papyrus reached out for the baby and carefully, gently patted their head. They allowed it after looking up at Sans, apparently deciding that if he didn't object to this loud person after all this time, it was probably fine. 

“THEY ARE SO FRAGILE,” Papyrus commented. His voice was filled with something like wonder. It was understandable; they had both grown up on legends of humanity's strength after all. Their powerful bodies housing powerful souls. Seeing a human so defenceless and with thin and fragile bones was subsequently a natural surprise. 

It also reminded Sans of an important matter. 

“they are,” he agreed. “paps… you know i love you and i trust you, you're my brother, but you didn't really answer earlier and i gotta make sure. ‘m sorry. but you won't tell undyne about this, will you? or asgore, or anyone else. no one can know.”

He felt a nervous energy inside of him that he found entirely atypical, that seemed as if it should belong to Papyrus instead. Sans usually never found it hard to stay still, it was actually his natural state of being, but right now he only managed because he was worried that I he suddenly moved, the baby might accidentally bump its head against Paps’ hand and hurt itself. 

“i mean,” he hurried to add, “i know it's your dream to be in the guard ‘n everything and to move up now that undyne made you a sentry and i’m really sorry for asking this, but it’s - i just…”

“SANS,” Papyrus spoke up when Sans’ words petered out, “I _PROMISE_.”

He didn't cry from relief, but it was a near thing. His brother knew what promises meant to him and the way he stressed the last word told Sans that Papyrus was well aware of this now more than ever.

“really?” he asked weakly.

“YES. I PROMISE. I WON'T TELL UNDYNE OR ASGORE OR ANY OTHER MONSTER IN THE UNDERGROUND. I WON'T TELL ANYONE. I'LL HELP YOU. YOU DON'T HAVE TO DO THIS ALL ALONE ANYMORE!”

“thanks.” 

He maybe sounded a bit choked, but he still didn't actually cry. The liquid magic emerging from his eye sockets was simply endless amounts of relief finding its way out of his body.


	10. What now?

**Notes for the Chapter:**

> This chapter was really difficult to write. I can normally force myself through this kind of trouble, but this time that didn't work. Sorry for the delay! At least it's nice and long :3
> 
>  
> 
> [Fanart tag](https://rehlia.tumblr.com/tagged/tbaab-fanart)

“yo, can you give me that wooden spoon? no, the other one.”

“SANS, DON’T VAGUELY WAVE YOUR ARM AROUND LIKE THAT! YOU’RE NOT HELPING!” 

“Adadadapapa!”

“EXACTLY!” 

“hey, don’t gang up on me.” 

He gave an overly sad look behind him, were Papyrus was holding the baby in his arms, rocking them a lot more strongly than Sans would have, which they apparently found great based on their loud, joyful squeals. Papyrus rolled his eyes, but the baby laughed even harder when they caught a glimpse of his expression, and that was good enough for Sans. With a wide grin, he took the spoon from Papyrus and turned back towards the stove focusing on the meal prep. 

Doing this while somebody else took care of the baby was _so much_ easier than it had been alone. 

So many things felt easier now that Sans had his brother to support him. While they still often had to take turns in order to make sure that they wouldn't both be conspicuously absent from their workplaces and general life, they often went to the ruins together, especially during the mornings and evenings. Like this, they could divide tasks and prepare for the times when they had to go alone. Fore example, one of them would hold and entertain the baby while the other prepared food for the day or cleaned up the house. Papyrus might distract the baby while Sans changed its diapers, or Sans might hum the baby to sleep while Papyrus did the dishes. So when Sans went alone or when he brought Papyrus over only to immediately leave again to be present at his sentry stations, the everything would be cleaned and prepared so a single person could take care of the baby without having to worry too much about household tasks. 

With the work divided it also got done much quicker, leaving both more time to actually interact with the child and for Sans to get adequate amounts of sleep. Managing the double life of being a sentry and an active member of his community, as well as a parent to a fussy little human, was still stressful and tiring. More often than not, Sans fell into bed and was asleep before he even properly sank into his sheets. But at least he got to sleep a decent amount at all, and in some ways, the tiredness helped. He woke up less often in the middle of the night, was less frequently plagued by nightmares or random bouts of insomnia in the aftermath of said nightmares. 

It was nice. 

There were still some things that he didn't have solutions for of course, mostly pertaining the baby's future in general. But with his brother helping him, he felt a lot more confident that he would be able to tackle those when they became relevant. Together with Papyrus, he would be able to find a solution for sure. 

“ok. i think this is done,” he announced after trying the food. The mashed vegetables were blended smoothly, but he had also added some small chunks in there this time. Since the baby's teeth kept growing, he thought it would be good if they had something to chew on. Nothing too hard of course, just a few soft chunks of potato. 

“THAT MAKES A POT OF MASHED PEAS, CARROTS AND POTATO BITS, A POT OF SWEET POTATO WITH BROCCOLI CHUNKS, AND A POT OF BLENDED BANANA AND APPLE, FOR THE NEXT DAYS.”

“yeah, should be enough to last us for a while,” Sans agreed as he began portioning the food into separate, smaller containers.

“Dada?”

“what, you want a spoon, kiddo?”

He grinned when he caught sight of the baby opening their mouth wide, eyes focused on the portioning spoon in his hand. Like a baby bird waiting for its mommy to give it a worm. Blowing on the food and testing if the temperature was mild enough for them, he moved over until he could feed them the morsel. They smacked their lips and clapped their hands in satisfaction at the taste. 

“Mmmmmh.”

“sounds like we got official approval,” Sans observed with a smile. 

“HOW CAN THEY EVEN BE HUNGRY AGAIN?!” Papyrus wondered when the baby opened their mouth once more after swallowing. 

“they're growing, you ate a lot of food too when you were small.”

“MAYBE THAT IS TRUE, BUT MY APPETITE DIDN'T COME WITH TERRIBLY STINKY CONSEQUENCES!” 

Sans laughed quietly, giving the baby another spoonful of vegetable mash. Papyrus was deeply enamoured with the baby, but he hadn't quite gotten over their gross bodily functions yet. 

“yeah, us monsters are lucky in that regard,” he said peacefully. 

“DO WE NEED TO CHANGE THEM TOO BEFORE WE LEAVE?” Papyrus wanted to know. 

“don’t think so, we only changed them when we came. they'll probably be good for a while even with the extra food,” Sans decided. 

“THAT'S GOOD! WE MIGHT HAVE BEEN LATE OTHERWISE, OUR SHIFTS START IN TEN MINUTES!”

“gotcha. let's see if we can set them up with their plushies so they won't be bored.”

He finished feeding the baby and put the newly portioned food containers away while Papyrus went to clean the baby's teeth, while loudly complaining about how gross their spit was. After that, they both sat down with the baby and played with them with their plushies, slowly letting them take over so they were playing peacefully by themselves by the time they had to leave. 

“that went well,” Sans sighed. 

“INDEED! WELL, I'M OFF TO MY STATION. I'LL MEET YOU HERE LATER!”

“sure thing. lunch at grillby’s today or are we gonna go then too?”

“I SAY GO! WE ONLY WENT TO GRILLBY’S TWO DAYS AGO!”

“true, but we're almost out of milk again,” Sans pointed out. 

Papyrus groaned in obvious displeasure, but ultimately nodded in defeat before he left. Sans watched his brother walk down the path until he vanished around the corner towards his own station. Despite understanding the necessity for a regular lunch at Grillby’s to get milk for the baby, Papyrus still didn't like being there. The grease just got to him. Now that they were both in on it, they both always ordered large glasses of milk to go, which meant that they had twice the amount of milk to store for the baby. It lasted longer, but they still needed regular trips to ensure that the baby would get enough of the stuff. 

His shift passed slowly and with the occasional trip to the ruins, a couple of minutes here and there. The baby seemed content, babbling and playing with their plush toys, and only needing a change once. It was as calm as a day could be and with the addition of being well rested after so much time of exhaustion, Sans felt pretty great. Telling his brother had really payed off, his worries about negative outcomes had proven to be unfounded, his life had gotten more stable and peaceful. 

Slowly, he pulled _her_ journal out of his hoodie pocket, looking at the worn cover. He hadn't really pulled it out ever since he had spread _her_ dust on it, not feeling strong enough to bear the sight. Today he felt he could. He still felt grief when he touched it, and looking at it now he was definitely sad. But it wasn't quite so heavy as it used to be, a feeling more bittersweet than completely black and insurmountable. He was doing better on all fronts. Briefly, he thought about opening the journal, about looking at pages shimmering with the residue of dust, at neat, cursive handwriting detailing moments of friendship and the final entries before a tragedy. 

But no. He wasn't quite ready for that yet. Perhaps in another month or two. 

He ran a hand over the cover, feeling how the knowledge that he was doing well and fulfilling his promise centered him. Then he put the journal back into his hoodie pocket, already hearing the footsteps of his brother approaching. 

They took a short time together in the ruins caring for the baby, before Sans brought him back for Papyrus’ second shift. Sans himself was still on his reduced work schedule, so he returned to the ruins in order to entertain the kid, try to teach them more words, and take a brief nap with them. His phone woke him up on time to pop back to the house, from where he walked outside pretending to have spent the entire time there resting. Nobody paid any attention to him as he walked up to Grillby’s and entered. 

“BROTHER! OVER HERE!”

Sans caught Papyrus’ waving, but not from his usual spot at the bar, where he and Sans tended to sit down for their lunch. Instead, he was sitting in one of the booths to the side.

Next to him was Undyne. 

He managed not to flinch or pause or otherwise show his surprise at her being here, thanks to years of trying to be unflappable. Internally though, he felt as if his bones had shrunk around his marrow, as if his body was too tight around his soul. 

What was she doing here?

“heya, bro. captain.”

“Don't call me that, you nerd, it's lunch, we're off duty!!” Undyne cackled. 

Sans slid into the booth, sitting opposite his brother and Undyne. Usually, he'd have no reason to assume that something was up. Undyne loved Grillby’s greasy food, the cheese fries in particular. But there was a fine sheen of sweat on Papyrus’ skull, turning his cheerful grin into something slightly less genuine. 

The anxious feeling inside of him intensified. 

“you ordered already?” he asked as casually as he could, glancing over at the menus. 

“YES! I THOUGHT IT WOULD BE NICE IF YOU ARRIVED AND THE FOOD WAS ALREADY ON ITS WAY! A THOUGHTFUL GESTURE FROM THE GREAT PAPYRUS!” Papyrus puffed up his ribcage, placing a hand on his sternum. The sweat on his skull didn't dissipate though. Sans wished he could ask Papyrus what exactly the situation was, but of course he couldn't with Undyne here. 

“nice. there it comes already.” He gave Grillby a nod when he brought the food to their table, carrying a large tablet to get all of their orders at once. A salad and a big cup of milk to go for Papyrus, a burger drowned in ketchup and another big cup of milk for Sans, and a big plate of cheese fries for Undyne. 

“Man, I've been craving these!” she said, immediately digging in with gusto as soon as her plate was in front of her. 

“thanks, grillbz.” 

Grillby gave them a nod that came with the crackling pop of fire on his head, before he returned to his usual place behind the bar. Sans took a hearty bite out of his burger, mostly because it was a good way to focus on something else but the anxiety suffusing him. Not that that worked. The flavour of the burger was amazing as always, but it honestly could have tasted like cardboard for how much attention he was paying to it. 

“So, what are you up to nowadays, huh?” Undyne suddenly asked him before popping two fries into her mouth, her sharp teeth making short work of them. Her single eye was boring into his eye lights, full of intention. 

Shit, she knew. She knew, and any second now she would flip over the table, pin him into place with ten spears, and roar at him to give up his secret. He was dead, he was…

He was an idiot. 

Calm down, he told himself. This wasn't about the baby. This was about how he was absent a lot and then dropped some of his shifts to rest better, as worked out with Papyrus. He hadn't seen Undyne ever since his brother had adjusted his work schedule and now she came to check on him like the imposing but ultimately deeply kind monster she was. 

“i’m good. better,” he told her, trying desperately to reign in the paranoid and panicked part of himself that insisted on this being the end of his brief stint as a father figure to a tiny little human. “i’m getting a lot more sleep now, so i feel more well rested. ‘m calmer at work ‘n stuff.”

“Well, that's good to hear. Your performance was bad before you dropped those shifts,” Undyne said, in a surprisingly kind voice. She almost sounded soft. That lasted for all of a second before she cackled loudly. “Like _really_ bad! I'd have said you're the worst sentry ever!”

“thanks.”

“Don't sound so proud of that!!”

A small laugh escaped him, genuine amusement bubbling up inside of him and managing to break through his panic. Yeah. This was good. It was just her being kind, taking an interest, being a good and caring boss while pretending to be tough. That was just who Undyne was. 

“what can i say. i’m lazy…”

“SANS NO!”

“...down to my bones.”

He winked, and both his brother and Undyne groaned loudly, although his brother was also grinning.

“THAT WAS TERRIBLE,” Papyrus complained around the grin that he simply didn't seem to be able to suppress. “ABSOLUTELY TERRIBLE!”

“aw. c’mon, you're smiling.”

“I AM MOST CERTAINLY NOT!”

“Fuhuhu, you two never change, do you?” Undyne threw in. 

“nope.”

“THEN WE WOULDN'T BE US ANYMORE, WOULD WE? WHILE I'M SURE MY LAZY BONES OF A BROTHER WOULD BENEFIT FROM THAT…” Papyrus threw him a deliberately put-upon glance that had Sans chuckle, “THAT WOULD ALSO MEAN NO MORE GREAT PAPYRUS! WHAT A TERRIBLE THOUGHT!” 

“You know what, I actually agree on that!” Undyne hollered. “Having you change would be the worst! You're a cool guy.”

“UNDYNE! THANK YOU!” Papyrus had sparkles in his sockets and a cute blush on his zygomatic arches, obviously more than happy at the compliment. 

“Don't act like I never tell you that!” Undyne laughed, pulling Papyrus over in a sideway hug and rubbing her knuckles over his skull. 

“NYOOHOHOOO, DON'T NOOGIE THE SKELETON!”

The two of them broke out into rambunctious laughter that had the whole bar looking at them, all the patrons smiling too. Sans chuckled along, the tightness in his bones finally unclenching. He may have cursed Undyne for a while, when she had been one of the big stress factors during his Waterfall shift. But she was a great friend to his brother and he couldn't truly dislike her. She was good for his bro. Seeing his brother so happy and playful with a friend made his soul feel warm. A short while after, they finished their food and it was time to return to work. Sans had his own shift in Hotland to attend to now, Papyrus was scheduled to patrol Snowdin Forest together with the canine unit. As per Sans’ request, Papyrus was never alone or on his own station when Sans wasn't there, despite his promotion. He would always patrol together with the dog monsters, or man his puzzles instead, to prevent him from ending up as the first alert. After his final shift, Papyrus would go to his training with Undyne, leaving Sans free to spend the rest of the afternoon with the baby at the ruins. First though, they needed to make a quick visit there to give the baby a proper lunch.

“SEE YOU LATER, UNDYNE!” 

Papyrus waved at her, already half-turned towards the exit of the town, opposite of where Undyne was headed. 

“Yeah, see you later. What about you?” Undyne asked, nodding at Sans. He had stayed next to his brother of course, intending to take them both to the baby as soon as they were out of sight. “Don't you have a shift in Hotland now?”

“i know a shortcut,” he quipped, winking at her. 

She grumbled in frustration at his behaviour, but finally turned around towards Waterfall. Sans and Papyrus turned fully and walked out of the town together, both carrying their cups of milk. Sans was lost in thought a little, but even Papyrus was quiet. There was no noise surrounding them.apart from the crunch of snow under their feet, their steps echoing as they walked together with their differently sized legs. Had something happened? He supposed he could ask his brother once they were in the Ruins, where they had nobody listening. They only needed to walk a bit further after they left the bridge behind them, just until the tree line. As soon as they were there, he could pop them both over to the Ruins without making people wonder why they both suddenly vanished. 

He pulled on his magic, feeling it flare and ready to pull them into the darkness of the shortcut. 

Just as he released it, he felt a smooth, cool, strong hand gripping his wrist hard, timed perfectly to get dragged through with them. 

He stumbled when he came out of the shortcut, his fight or flight instinct automatically trying to jerk away from whoever was holding him, but the hand didn't budge. 

“Fuhuhu. I _knew_ you were up to someth - “

“Dada? Papa?”

“OH NO!” 

They were in the baby's room together. Undyne had her hands clasped around one of Sans’ and one of Papyrus’ arms. Her grip didn't even loosen when she caught sight of the baby, her one eye growing huge and round. 

“no - “ 

Sans pulled on his magic as fast as he could, trying to initiate another shortcut to bring Undyne away from the baby. But while his reflexes were quick and sharp, he didn't have her soldier training, nor her rage fuelling her. She let go just as he was ready to pop them away and had her own magic crackling in her hands immediately, preventing him from pulling her away even without direct contact. 

Time seemed to slow down. 

Undyne had her spears, bolts of energy bursting away from them, betraying her agitated mindset. 

Papyrus likewise had already summoned his bone attacks, raising them up to deflect her. 

Sans… 

Sans had always prided himself on his ability to think fast, on how his reactions were quick and clever despite his usual laziness, on how nothing could really catch him off guard. He had his shortcuts, his blasters, several clever bone attacks that he observed his brother doing and then modified for himself. He had figured out how to circumvent several of the problems he might have in an encounter to fight more efficiently. 

All of that went out of the window. 

The instant he saw a warrior raise a weapon against his baby, he knew only to do one thing. 

Out of sheer panic, he threw himself forwards, in the way of Undyne’s spears. He stumbled to his knees and pulled the baby into his arms, pressing them to his chest and curling his body around them, back to Undyne, acting as a living shield for his kid. He had his eyes scrunched shut and was fully prepared to sacrifice himself if necessary. 

It was only when nothing happened and the room was abruptly silent that it hit him how outrageous his thought process was. He slowly blinked his eyes open, turning his head to look behind him. 

Undyne was staring at him in utter disbelief, spears still in hand, the energy on them having calmed. She didn't seem to notice at all that Papyrus had turned her soul blue and additionally pinned her into place with a couple of well placed bone attacks. There wasn't an attempt to move from her. She simply kept staring at him and he back at her, their eyes unable to flicker aside even for a moment. 

In his arms, the baby began to cry, breaking the tense moment with their loud voice. 

“no, shh, sweetie, it's okay. it's okay. don't cry.” He hugged them closer and began rocking them gently, out of sheer habit. 

“What the _hell_ is going on here!” Undyne roared, making the baby cry even louder.

“W-WE CAN EXPLAIN!” Papyrus offered. 

“Explain? _Explain_?!? That's a human!” Undyne pointed an accusatory finger at Sans and the baby. “That's the last soul we need to finally get out of this fucking mountain! And you're protecting it?! You should be taking its soul!”

“it’s a baby,” Sans pointed out angrily, despite knowing that this hadn't bothered him initially either. 

“So?! The other souls were kids, we got their souls anyway!”

“UNDYNE!” Papyrus sounded angrier than Sans had ever heard him. Genuinely furious, with a dash of disappointment on the side. 

“I _knew_ you you weren't ready! This is why I didn't want to make you a guard! You're too soft! I shouldn't have listened to you! I thought you finally got it when you told me you knew what it entails but I should've listened to my gut! You don't have what it takes to be a guardsman!” Undyne shouted, apparently uncaring how much her words hurt Papyrus. 

Sans watched his brother falter but only for a second. He had no chance to jump into the conversation before Papyrus was speaking again. 

“IF THE SIGN OF A TRUE GUARDSMAN IS THAT HE MURDERS INNOCENT LITTLE BABIES, THEN I DON'T WANT TO BE ONE!” Papyrus exclaimed with unshakable conviction. “THAT IS NOT RIGHT.”

“It's right! It’s about our freedom!” Undyne’s voice cracked somewhere in the middle of that sentence, the pain she felt herself no longer repressible. “It's about all of us, all monsters! What about _our_ kids?! The monster ones? Don't you want them to be free? To see the sky and the sun? Are you okay with all of us just being stuck down here forever so you don't have to get some blood on your hands?!” 

“BUT WHAT WILL THE HUMANS THINK OF US IF WE COME OUT OF THE MOUNTAIN AND WE KILLED ALL THEIR CHILDREN? THEN WE ARE FREE BUT AT WAR. HOW IS THAT BETTER FOR MONSTER CHILDREN?”

“I - that's - we can beat them if we have to!” Undyne insisted, although this particular argument definitely hits her harder than anticipated. She was brash, but not stupid. She knew how the last war had ended. 

In the slightly uneasy silence after her statement, Sans managed to finally climb to his feet and stand up, still holding the baby close to his chest. He kept himself angled away despite seeing how tightly restrained Undyne was. He didn't feel comfortable holding the baby in her direction. They weren't crying loudly right now, but they kept whimpering throughout the whole loud argument. Sans gave them a soft nuzzle.

“hey, it's fine. we're just, uh… debating. no need to cry, huh?” His soft voice didn't get them to stop the whimpering. They still had their eyes scrunched up and their mouth in a pout, tears trickling over their chubby little cheeks. 

Sans wished he could make the tears cease and their expression ease. Last time they cried about a loud stranger, he had been able to reassure them by touching Papyrus and joking around, using his own good mood and the undertone of hope in his demeanour to ease their fears. He had nothing like that to offer now. He didn't even dare turning towards Undyne fully out of fear that she might break through her restrains and try to hurt his baby. 

“Since when are you such a mother hen anyway?!” Undyne demanded to know, suddenly but now with more heat in her voice again. 

“i found them in the ruins months ago,” he said. “the door was open even though it never had been before - “

“And you didn't report it?!”

“i promised the lady behind the door i would… protect any humans that came from there. she was important to me. she was my best friend.”

Undyne looked, if possible, even more outraged than before. To her credit, she didn’t interrupt him at least. Something about his statement seemed to have made her think. So he kept going and told her the entire story, just like he had with Papyrus. How he had found the door open, with the baby and the corpse lying just inside. How he had initially summoned a bone to kill the baby for its soul. How he had hesitated, his journey through the ruins and the discovery of the massacre within, how he had spread their dust and buried the dead murderer. How he had initially despised the baby, only to come to recognise their innocence later, how he had cared for and come to care about them. 

The steady cadence of his voice had a soothing effect on the baby too, who finally stopped whimpering. They looked at Undyne with the same kind of skepticism that they had initially shown Papyrus, but there was a lot of curiosity in their eyes too.

Undyne was squirming under their gaze. She seemed to try not to look at them, but her singular eye kept sliding from Sans’ face down to the baby in his arms, meeting their brown eyes for seconds before she looked away again. Occasionally, she looked at his hands instead, at the way he was holding the baby. Papyrus was slowly loosening the restraints he had put on her, although he kept a wary glance on her, the tension in his bones betraying that he was ready to put them back up at a moments notice if she started flinging spears again. 

But by the time Sans was finished, she was merely dragging a hand over her face, clearly pissed, but not inherently aggressive anymore. Not that Sans didn't still feel wary, about her and about the situation in general.

“Ugh, I can't believe you two. The salvation of monsterkind is in your hands and you go and play happy family!” She dragged the hand down and fixed her stare on Sans again. “Since when are _you_ such a dad anyway?! I thought that was his job!”

“heh. i know,” Sans said with a shrug. 

“UNDYNE THAT IS VERY RUDE! SANS HAS ALWAYS TAKEN GOOD CARE OF ME AND HE WORKS REALLY HARD FOR THE BABY'S SAKE TOO!” Papyrus chided her. 

“aw, thanks bro,” Sans smiled, genuinely touched by the assessment. 

“Would be nice if you could work that hard on your sentry post,” Undyne snapped, only to immediately glare at him and then at the baby. A light seemed to go on in the back of her head. “What, was that it? You kept skipping your shifts just to look after this… this human meatsack?!”

“DON'T CALL THEM THAT!”

“i mean, technically i was watching for humans, just like the job description said,” Sans pointed out with a grin.

Judging by the increasingly wild look on Undyne’s face, she found that revelation a lot less funny than he did.

“Nnggaaaaaah! You should have watched for humans the usual way! If you couldn't do it then why didn't you bring them to me?!” she demanded to know. 

“i told you, i made a promise. and then i cared too much,” Sans defended his decision. “you keep acting as if you would've acted different in my position, but… imagine if it had been asgore. imagine he died suddenly. wouldn't you try to do everything to honour his last request?”

There was no need for Undyne to answer, save for looking to the side with a scowl. She was already trying to live up to the expectations of the monster who had trained her. Who had almost helped raise her. 

It was a manipulative way to phrase things. By bringing Asgore into things he had not only appealed to her strong sense of duty and affection towards the king, he had also brought her relationship into the discussion, the way she and Asgore were almost like daughter and father. By doing this, Undyne wouldn't be able to ignore how Sans’ own paternal feelings towards the baby had compelled him to act. Sans knew that, he could see that Papyrus had noticed, and Undyne must have noticed too. But he didn't care. 

“Asgore would never have asked me to save a human and leave the monsters down here,” Undyne protested, but her voice was weak. 

“no. but my friend did. and i couldn't ignore her last wish,” Sans insisted. 

“So what, that's it now?” Undyne asked. She sounded almost pleading despite her still angry tone. “You want me to accept this and then we'll all… pretend this never happened? And monsters stay trapped here forever? And what, that kid grows up here all alone, kept a secret until it dies? Do we get out then? What if another human falls down here, huh? What if they harm the kid? What's your plan?”

“THEY’RE NOT ALONE! THEY HAVE SANS AND ME! AND MAYBE… YOU?” Papyrus offered. He looked hopeful, although in a strained way that betrayed his awareness that this was unlikely. 

Predictably, Undyne huffed and didn’t even grace the statement with a reply. 

“i don't know about the future,” Sans admitted. “i’ve been thinking about that too.”

“You don't know?!”

“no. i was kinda busy making sure they survive and don't hurt themselves while i was gone and feeding them without knowing what they should even be eating and getting them to stop crying when they had a fit and cleaning them and trying to get enough sleep and avoid being discovered while doing all of that,” Sans snapped. 

Undyne huffed. 

“Well, great. So you expect me to keep quiet about this even though I know that you're bullshitting it?!” She jabbed a finger towards him, getting louder again as her temper rose with this new development. “I get trying to keep your promise and becoming attached, but what about my promise to Asgore, huh? What about my promises to the guard and the population? What about the people I care about? I was always ready to set them free! And now you want me to do nothing just so you don't have to feel sad about your dumb human adoptee?!”

“i won't let you kill my kid,” Sans growled. He knew Undyne was making some good points. She was pointing out things that he himself had wondered about, problems he had already identified himself. Maybe that was what hurt so much. He knew she was right in a way, but he couldn't accept it, because that would mean accepting the unthinkable. 

“It's not even your kid!” Undyne complained. “You just happened to look after them for a bit!”

“like asgore happened to look after you for a bit?” Sans bit back. 

“That's not the same!” 

“he practically adopted you. i did the same with this baby, they're my kid and you're not getting them and that's final.”

“So what are you going to do?” Undyne challenged him with a scoff. “You can’t keep me here forever.”

“but i can stay here forever,” Sans said calmly. 

It was only after the words left his mouth that he realised what he had said. He felt his own eye sockets widen without his input. 

Was he really ready for that?

It would be a lonely existence. Lonelier than even _she_ had been. There were no more monsters here, nobody to give him company. Only him and the baby. Exactly what the baby themselves were looking forwards to if he kept them in the Underground. It hadn’t been easy to make that decision for them, even though it was for their own safety. It was even harder to make it for himself. The baby wouldn’t know exactly what they were missing, but he would. Then again, did that even matter? He had never seen the surface, and yet he yearned for it. 

What was he doing? 

But there was no alternative. He couldn’t think of anything that would allow him to save the baby except this. Undyne, as predicted, was intent on obtaining the last soul to free them all. The other monsters would be no different. Papyrus was an exception, something truly special. The other monsters were filled with love and hope and compassion, but even they wouldn’t be able to resist the temptation for freedom. He had no other choice. 

The stronger his conviction grew, the more horrified Undyne looked. 

“You can’t be serious!”

“the lady who lived here managed to survive all those years… i’m sure i’ll manage too, somehow.” 

His voice carried a finality to it that scared even himself. Papyrus looked surprised too, but if possible even more determined than Sans himself. His brother was apparently ready to stand by his decision, even though Sans hadn’t even asked him. What had he ever done to deserve such a wonderful brother? 

“Dada?” 

The baby had been relatively quiet after they had stopped crying and whimpering, mostly clinging to his chest and hiding their face in his hoodie, not liking the arguing and the loud voices. Jeez, he probably should have just brought them away. They shouldn’t have had to be stressed out like this. At the same time, now that it had happened he felt that they’d be too frightened to be left alone. They’d feel abandoned and start crying for sure. 

They were looking up at him, perhaps because there had been a moment where he and Undyne didn’t shout at each other. They were looking unhappy and scared, their face pulled into a frown. They kept glancing over at Undyne in an insecure way, but mostly kept their eyes on him. He knew his own expression must be tight, and not reassuring for someone who couldn’t even understand what was going on. 

He tried to rearrange his face into something gentler and friendlier, tried to fill his eye lights with affection to reassure them. It wasn’t easy in his current mood. He felt too cornered and scared about their and his own future to really manage.

“hey… i’m sorry. did we scare you? it’s gonna be fine, don’t worry. i… i’m working something out, okay?” He was definitely babbling a little and he knew it. He just wanted them to feel okay. He just wanted for everything to be okay… why did Undyne have to grab him and follow them here? Why couldn’t she just have stayed out of his business? 

Sans didn’t even notice how he was hunching over, pressing the baby as closely to him as he could without hurting them. He didn’t know what to do. 

He had tried so hard, put his everything into protecting them, and now this. 

Was this how _she_ had felt? Was something like this why _she_ had him promise to protect any human that came out of the ruins? Any human that, by necessity, would have slipped past _her_? If it was, he now had a newfound appreciation for the request. This hurt. Even the mere idea of having his baby taken from him and killed for their soul was beyond painful. Despite his increasing affection and acknowledgement of this affection, he hadn’t known the true depth of his feelings until the moment the baby’s life had been in danger. He hadn’t known how far he was willing to go, not to fulfill a promise but simply to make sure that they were alive and safe and happy. 

“This is so fucked up,” Undyne groans. 

“UNDYNE! DON’T SAY SUCH WORDS IN FRONT OF AN INFANT!” Papyrus chided her. 

“They don’t even speak!” Undyne protested. “Apart from calling him daddy for some reason.” 

“DADA, NOT DADDY! AND I’M THEIR PAPA!” 

“Oh hell,” Undyne groaned. 

“REALLY UNDYNE, YOU MUST WATCH YOUR LANGUAGE! WHO KNOWS WHAT THEY MIGHT START REPEATING OTHERWISE! THEY ARE TINY AND INNOCENT, BUT THEY ARE VERY CLEVER!” Papyrus’ pride was palpable as he was speaking. 

“So you’re what, their uncle? How long have you been keeping all of this a secret from me, huh?” Undyne sounded betrayed. It was clear that she took this personally. If there had ever been any doubt about how genuine her feelings of friendship for Papyrus were, this moment would have cleared them. Even in her rage towards Sans she hadn’t sounded this wounded about it. 

“NOT AS LONG AS SANS,” Papyrus explained, staying surprisingly calm in spite of everything. “HE ONLY SHOWED ME RECENTLY. IT’S NOT EASY TO TRUST SOMEONE WITH A BIG SECRET LIKE THIS!”

The pointed look he gave Undyne didn’t fully curb her own insulted stare, but it did make her squirm a little. She had barged in, not waiting for anyone to feel ready to confide in her. As brash as she was, she could probably recognise that this felt like a betrayal to Sans and Papyrus too. 

“This shouldn’t have been a secret,” she insisted, stubborn to the last moment, but there was no more fire in it. 

“I DON’T THINK WE’RE GETTING ANYWHERE ARGUING LIKE THIS,” Papyrus said, in that forcibly cheerful way that was him trying to make reality comply with what he wished the situation was like. “WHY DON’T WE TAKE A SHORT BREAK AND TALK MORE LATER WHEN WE’VE CALMED DOWN?” 

“I don’t want to calm down!” Undyne complained. 

“what if she runs away?” Sans asked. 

“SANS…” Papyrus was stepping from one foot to the other uncomfortably. “WE CAN’T KEEP HER HERE FOREVER. DON’T YOU SEE IT’S A GOOD IDEA? WE CAN ALL TRY TO CALM DOWN AND THEN GET BACK TOGETHER AND TRY TO WORK ON A SOLUTION!”

He sounded hopeful, as if the lack of teamwork was the only thing preventing them from solving this conflict of interest. 

“IN THE MEANTIME, WHY DON’T WE CLEAN THE MESS HERE AND FEED THE BABY?” 

Sans hadn’t even noticed any mess in all the panic, but when he looked down now, he found that he was standing in a giant puddle of milk. The cup he had been carrying from Grillby’s laid abandoned nearby on the floor. He must have dropped it when he dove forwards to protect the baby. He sighed deeply. He hated it when there was a mess on the blankets. 

“fine,” he mumbled. Papyrus was right about one thing after all; they couldn’t keep Undyne here forever. Whether she ran now or they brought her back to Snowdin later, it didn’t matter. It didn’t change anything.

“HERE, WHY DON’T YOU FEED THE BABY MY MILK OUTSIDE, AND I’LL GATHER UP THE BLANKETS TO WASH!” Papyrus had somehow managed to keep his own cup of milk intact, and he handed it over to Sans now before walking into a corner and gathering up the plushies, checking if they had milk on them too before marching out of the room. 

Undyne and Sans stared at each other for a moment, then she left after Papyrus. Sans followed more slowly. He found her in the hallway, taking the interior in with a curious expression. Apparently she was content to stay around them for now, instead of running and immediately alerting the guard as he had feared.

“the kitchen is that way,” Sans pointed out, directing her through the living room. He stayed behind her, not really trusting her to walk at his back. It was safer this way. In the background, he heard Papyrus take the blankets out of the room and to the bathroom. They had set up a laundry corner with washing powder and a second stash of blankets in the house, just in case. The precaution was paying off now, because Papyrus could clean the dirty blankets and put up the new ones, so the baby wouldn’t be left without soft coverings.

“Huh,” Undyne said in front of him. “Looks like Asgore’s house. Just not as grey.” 

That was true, actually. Sans hadn’t been in the castle that often, so he hadn’t immediately noticed. But it was true. He wondered what that meant, but then he pushed the thought aside when he noticed the baby tugging at the cup he was holding in his other hand. 

“sorry, i know you’re hungry,” he mumbled. Undyne turned and stared at him again, but he ignored her and took a shortcut into the kitchen instead of walking past her. Like this, there was not a single second where he had his back to her. Paranoid perhaps, but it made him feel better. He attached the modified rubber glove he had made for the baby to drink from to the cup and began to feed them. 

The baby got comfortable in his arms, drinking peacefully. Now that nobody was shouting or otherwise being upset, they were calm and not fussy anymore. Not even Undyne’s continued presence seemed to bother them. Some peace and quiet and a big helping of milk while he was holding them was apparently all they needed to feel good again. Perhaps it was partially thanks to Papyrus. They had already recently had to learn to tolerate a loud stranger around them, so maybe it was easier for them to do it again with Undyne now. 

Not that this would be necessary for the long term, most likely. 

Sans didn’t believe that Undyne would change her mind. She was watching him and the baby now with an incredulous expression, though thankfully she didn’t use Papyrus’ absence to try anything, like having another go at the baby’s soul. He kept an eye on her regardless of course. 

The baby was soon done with the milk, and he put the leftovers away in the fridge. Then he began walking with them, rocking them to get them to burp. It didn’t take long. 

“Errp,” made the baby. 

“What on earth are you doing?” Undyne asked him, the corners of her mouth twitching slightly. 

“prevents gas to build up in their stomach,” he explained. “otherwise it’ll hurt them and kind of, uh, explode out at some point.”

“Babies can explode?!” 

“not literally. but in a way… i call them the legendary fartmaster.”

The snort was small, but it was there. Unlike his brother, Undyne was absolutely the kind of person to find that hilarious. She had fewer hangups about gross bodily functions and her sense of humour went along accordingly. If she and Sans didn’t constantly bicker about his job performance, they might have actually gotten along before all of this went down. 

Too late now. 

“Dada!”

The baby was twisting in his arms, trying to twist into a more upright position. He complied and had them sit on his iliac crest, one arm wrapped around them, so they could look around easily. 

“Ahm, ahm!” They patted their hand against his teeth, looking up at him expectantly. He indulged them and pretended to bite them, touching their tiny hand only ever so slightly with his big blunt teeth. 

“grrr,” he made, the growl obviously fake. He didn't want to scare them after all the shouting just now. 

They giggled happily. Then they turned to Undyne, reaching their hand into her direction while giving Sans a questioning look. “Ahm?”

“that’s probably not a good idea,” Sans said quickly, taking their hand in his own and pulling it back towards his chest. He gave Undyne a look, intending to dare her to come and try biting his baby, but he paused when he found her looking at them both with a conflicted expression on her face. He could feel his own face shift into something pleading instead, silently begging her to understand what this meant to him, why he was acting the way he did. 

“I’M DONE WITH THE LAUNDRY! I DIDN’T HEAR YOU SHOUT SO I’M ASSUMING YOU GOT ALONG!” Papyrus’ sudden appearance and his volume had Sans, Undyne and the baby flinch as one, all startled.

“Cool, then you can bring me back now,” Undyne immediately demanded, looking away from Sans and the baby.

“BUT WE NEED TO THINK ABOUT A SOLUTION TOGETHER!” Papyrus protested. 

“I need to think about this by myself first,” Undyne insisted. “I want to sleep about it before I talk it over again.”

“OH. A NIGHT TO FOCUS YOUR THOUGHTS LIKE A TRUE WARRIOR? I SEE!” He turned towards Sans, half questioning and half expectant. 

He had half a mind to decline, but it course that would have been futile. One way or another, Undyne would get out of here, either being taken by him or clawing her way out. They really couldn't keep her here forever. And Sans didn't want to fight her, and he knew that Papyrus didn't either. 

“i’ll bring the baby to their room,” he said.

He used a shortcut, leaving Undyne and Papyrus alone in the kitchen for now. The baby's room had fresh blankets spread on the floor, spreading the clean, mildly floral scent of the washing powder in the air. He could hear his brother and Undyne talk in the kitchen as he sat the baby down on the blankets, crouching down to be closer to their eye level for a bit. 

“Dada?” they asked, their face scrunched up. 

They never particularly liked it when he left. They had gotten better about it now that they were alone less often thanks to his reduced shifts and the support of his brother. But they still didn't really like it and it had never hurt him as much as it did now. 

“i gotta go,” he said quietly, running a hand over their head, feeling the soft fuzz of their hair under his phalanges. 

“Dada ahm!” they demanded, reaching their hands out for his face once more. 

“Ahm,” he said as he carefully pretended to bite them. 

They giggled, but even though he tried he couldn't smile the way he wanted to. 

“Dada?”

They didn't understand. They had no idea what just happened. What was looming in the future, his and theirs.

“i love you,” he told them, knowing that they wouldn't understand this either. 

He gave them a nuzzle, got up, and went back to the kitchen. 

“ready to go?” he asked without preamble, not caring that he was interrupting Undyne and Papyrus. He wanted to know what they had been talking about, but at the same time it seemed so irrelevant. 

“I AM!”

“Just do it already!”

He chose the path leading up to Snowdin as his arrival point, just behind the curve in the forest, the same spot that he'd started from. How stupid he had been then. He had seen that something was up between Undyne and Papyrus, but he had been lulled into security by their comfortable companionship at Grillby’s. He should have been more careful, more aware, more…

Undyne didn't run immediately after they arrived, which was already more than he had expected. Not that he planned to make much more chit chat now.

“well, here we are,” he said dully. “i guess we'll hear from you soon at our stations.”

“Feel free to take the rest of the day off,” Undyne said. “Both of you.”

Silence descended over them. 

“ARE WE FIRED?” Papyrus asked anxiously.

“No. But I you'll be useless today anyway. Take the time and think properly,” Undyne insisted. 

Did she hope that they'd change their minds? Or was this her way of telling them to take as much time with the baby as possible before she brought hell down on them? Sans didn't know, but he didn't get to ask either, because Undyne turned and started to walk towards Snowdin, posture tense and movements abrupt. 

“UHM. SO SHOULD WE GO AND COOK, SINCE WE HAVE THE AFTERNOON OFF?”

“yeah. sure.”

Sans wasn't sure if it wouldn't be a better idea to use the time and meet some monsters. If Undyne went to the guard, and decided to corner them, this would be their last chance at company before they went into exile. But then Papyrus didn't have a lot of friends, and Sans cared more about paps than any other monster out here. An afternoon between the two of them, being in their house and pretending the world hadn't crashed down around them… that sounded nice. 

It was nice, even though they were both unable to relax, flinching at every loud sound that echoed in from the outside, anything that came too close to their house. They had fun cooking, Sans told a barrage of puns, Papyrus scolded him, Sans fed his pet rock, Papyrus did the dishes. But Papyrus didn't insist that Sans pick up his socks, nor did he do his usual evening cleaning. Sans didn't leave for another round at Grillby’s, instead packing some things from his and his brother's room into a bag, added to some supplies from his secret workshop. They watched the evening news together holding their breaths, waiting for Mettaton to drop the bomb instead of rattling off the usual trivialities of another day passed in the Underground. 

And that night, neither of them slept.


	11. Better than any of us

**Notes for the Chapter:**

> [Fanart tag](https://rehlia.tumblr.com/tagged/tbaab-fanart)

They were at the breakfast table, mechanically working their way through two bowls of oatmeal for a change, when they heard the knock at the door. 

Both of their heads immediately shot up and they stared at each other across the table.

“don’t open,” Sans hissed when Papyrus got up. “we gotta leave.”

“We don't know that yet,” Papyrus insisted, lowering his voice too so nothing would be heard outside. “It's probably just Undyne to tell us how she decided.”

“do you really think undyne would be so quiet? or patient?” Sans challenged. 

“After yesterday she might be,” Papyrus argued. 

That might be true. 

Still, Sans felt suspicious. Undyne wasn't like this at all. Tension spread through his body, but he decided to work with his brother for now. 

“stay out of reach,” he ordered, getting up and moving directly to Papyrus’ side. He wrapped his phalanges around his brother's arm. “if anyone tries to grab us, i’ll take a shortcut.”

Papyrus nodded and Sans readied his magic. It wouldn't be like yesterday, where he couldn't get his magic going fast enough, or that someone grabbed onto them at the last second. They were ready to bolt at the first sign of danger. 

When Papyrus opened the door, it indeed wasn't Undyne who was waiting for them. Instead, Dogaressa and Dogamy stood there, ears flat and eyes worried. They both looked deeply unhappy. Sans immediately felt nervous, suspecting that Undyne had brought the guard to their house, but he couldn't see the rest of the Snowdin Canine Unit, nor any of the guards from Hotland, the Core, or New Home. From what he could spot through the door and the large living room window, the other Snowdin residents were going about their day as always, nothing indicating that anything unusual was going on. 

“SORRY FOR THE WAIT,” Papyrus told them, so chipper that even Sans would have had trouble to detect some hung was off, if he hadn't already known. “I HAD A POT OF SPAGHETTI BOILING THAT I NEEDED TO PUT AWAY FIRST.”

“We don't want to disturb you,” Dogamy whined. 

“May we come in?” Dogaressa requested. 

Sans and Papyrus glanced at each other. Sans thought it was a bad idea - it might be a trap. But on the other hand, it was better than being asked to come outside, where they might get surrounded. He didn't want to, but Sans knew that they could take on the dogi if push came to shove. 

“where’s undyne?” he asked before Papyrus could reply either way. 

Both of the dogi whined, their tails firmly between their legs. 

“That is why we need to talk,” Dogamy told them, his voice now a whisper. He looked around nervously. 

“Nobody but the guard is supposed to be told yet,” Dogaressa whispered, looking equally nervous. 

The bad feeling in Sans’ soul grew, but Papyrus apparently decided that it would be better to continue the talk on the inside, stepping aside to let the couple in. They both made their way inside and closed the door behind them immediately, heightening the feeling of being trapped. They didn't approach yet though, both looking at Sans and Papyrus with the saddest puppy dog eyes imaginable. Sans braced himself for the worst. 

“It's about Undyne,” Dogamy began. 

“We still cannot believe it,” Dogaressa whimpered. 

“WHAT HAPPENED?” Papyrus asked. 

By now, sweat was gathering on both on their skulls. Sans could feel how tense his brother was, the joints of his arm taut under Sans’ phalanges. 

“She has vanished,” Dogamy said, sounding pained as if he had been hit. 

“wait, what?!” Sans blurted out, feeling completely blindsided by this development. Papyrus looked equally baffled. 

“We should start at the beginning, puppy,” Dogaressa told her husband, clearly trying to stay strong despite the fact that she was quite obviously feeling equally hurt. She turned back to them and took over for now. “When the king entered his throne room this morning, he found a note, signed by her. It stated that she intended to set us all free. He found... “

“He found one of the souls missing when he checked,” Dogamy took over when his wife couldn't speak anymore. “As the captain, Undyne had been shown where they are kept in order to be able to protect them should anything happen to the king. We were called in, and her smell ended at the barrier.”

“She must have crossed it,” Dogaressa finished. “But nobody knows why she would do something so drastic. The king said it's too dangerous… everyone knows what happened to the prince and his sibling...”

“He wants the guard to spread the word, but only among ourselves for now,” Dogamy joined in again. “If the populace found out Undyne took a soul, there might be a panic and monsters could lose hope and fall down. We heard it just now from R01 and R02, they took the ferry to Snowdin and met us at the dock before we went to work. They said if anyone has information we are supposed to report directly to the king.”

Sans stared at them, unable to formulate his thoughts, unable to even really think at all. He was stunned and had no idea what to feel about this. 

They had thought there were only two solutions to their dilemma, protection or betrayal. 

Undyne had opted for a third. 

But just like any other monster, Sans knew the story of the lost prince and his sibling. He was well aware that even with the power a single human soul could grant a monster, there was no guarantee that it was enough to take on the surface. Even a warrior so strong as Undyne, so determined and experienced, could easily falter under the combined might of the human population. That was why Asgore had decided to wait until seven human souls were gathered. That was why he wanted to become a god before leading the monsters to freedom. It was the only way he felt safe enough to grant them a peaceful existence on the surface, a fact that all monster children learned very early in school, and the reason why everyone was content to wait until the collection was complete. 

For Undyne to have decided to throw Asgore’s decision aside… it was tantamount to blasphemy. 

Monsters generally didn't fight against Asgore's plan, too scared of the humans. There might sometimes be monsters who questioned the logic, but then Asgore would always tell them to feel free to drop by for tea, and gently explain his thought process to them, enriched by the painful details of his own son’s demise. Nobody knew where exactly he stored the souls, but the truth was that very few monsters would even think of stealing them, or have the balls to do so. Undyne had practically been raised by Asgore, groomed for command, and he had trusted her with the information because he knew he could rely on her. Because he had worried that without her as a backup, if something should happen to him, the monsters would be left with no access to the souls they had gathered.

Her betrayal was unthinkable. 

And all because of him. 

She never would have done something so extreme if it hadn't been for Sans, for the guilt he had induced in her yesterday. He didn't think that his words and deeds would have such a strong effect on her, had already counted this situation as lost. But he must have shaken her moral convictions up more than he thought. 

“Wowie,” Papyrus finally said. He didn't sound impressed or excited like he usually did when he used the phrase though. He only sounded scared.

“It's a shock for all of us,” Dogaressa nodded sadly. “She out of everyone was supposed to be better than this…”

“Perhaps it's all a misunderstanding,” Dogamy whined. 

“I hope so,” Dogaressa agreed. “So please… if you know something…” 

“You were her closest friend,” Dogamy added, his sad eyes fixed on Papyrus now. 

Papyrus flushed, looking extremely conflicted. To have his close friendship to Undyne recognised would normally fill him with glee, but right now it was clear to Sans that his brother felt guilty for what was happening too. They had both done their parts, had both put pressure on Undyne after she had discovered their secret. 

“I'm sorry,” Papyrus whispered. 

The dogi understood it in the only way they could, missing vital pieces of information. 

“It's okay,” Dogamy said, putting a paw on Papyrus’ hand. “It was a long shot to think she might have said something to you.”

“Nobody could have anticipated this,” Dogaressa nodded, patting Papyrus’ other hand. “Just think about it. If there is anything at all, anything off even during the past weeks…” 

Papyrus nodded mutely. 

“We should go,” Dogamy stated, pulling his paw back. “We need to tell the rest of the unit.”

“Lesser Dog was with us at the dock,” Dogaressa informed them. “But not Greater Dog and Doggo. If you come across them on your way to your stations, please inform them if we haven't already. Sometimes you move faster than we do.”

They looked at Sans and Papyrus expectantly, and Sans was finally the one to agree when it didn't seem as if his brother would be able to. Immediately after he had agreed, the dogi saluted and left. 

Silence descended over the house. Neither Papyrus nor Sans were able to speak, too shocked by what they had just heard. 

“Do you think it's a trap?” Papyrus eventually asked, after a time that seemed like an eternity had passed. 

“dunno,” Sans said, surprised that his brother would question this before he did. Normally, Papyrus was far less suspicious than Sans was. “seems convoluted. if they wanted to corner us, it would've been easier to bring the whole guard here and catch us in our sleep or on the streets. or even in the forest where they could hide among the trees, if they didn't want to unsettle the population.”

“Then should we say something?” Papyrus was looking at Sans with a lost expression. He seemed completely floored by Undyne’s decision, and not knowing how to react or what to do. It made him look younger than he was and made Sans feel incredibly protective about him in a specific way he hadn't felt in years. It was tugging at his instincts as an older brother, pushing him to gather his thoughts and take the lead where for years now, he had stepped back and mostly allowed his brother to make his own choices for his adult life. But now he had to be strong for his little brother, even though he felt list himself.

“difficult to say,” he reasoned. “on one hand, leaving asgore in the dark about undyne’s motivation will cause him a lot of grief. and if she… i mean.”

He didn't want to say it. The possibility was too terrible to even contemplate, especially with how wounded Papyrus looked at the mere suggestion. But it was also likely and Sans had learned by now that it was ultimately better to confront the painful death of a loved one outright, to be able to grieve and get closure. Even Papyrus had seemed better after he had been able to bury his flower friend, after he had started taking care of the grave. 

“if she doesn't come back,” Sans forced out and they both winced. “then the underground will at some point learn what happened and monsters will definitely fall down over their hero betraying them. if we tell asgore, he can plan for the possibility and make sure to keep the populace calm.”

He sorted his thoughts before going on. 

“but if we do tell him, he might also want the baby. to get the count back up. then we'd have the same situation we had with undyne again, only with asgore.”

It was harsh, but it was a definite possibility.   
Asgore hadn't been happy that all the humans who had fallen so far had been children from what Sans knew, but the King had taken their souls still, feeling it was his necessary duty. 

Papyrus kept quiet for a while after his explanation. It was clear that he felt tremendously guilty about what happened, and Sans knew it would only get worse if Undyne indeed didn't return. If he was honest with himself, he felt pretty shitty right now too. He didn't want to be responsible for Undyne’s death, or for possibly causing many more monsters to fall down. 

“I think we should say something,” Papyrus finally said. “If monsters could fall down if we don't it would be wrong to keep quiet.”

“guess so,” Sans mumbled. On one hand, he hated the idea of voluntarily endangering their lives again. On the other hand, how could he endanger the lives of monsters in such a way after having only recently experienced the grief of losing someone himself? That was impossible. He had already resigned himself to a lonely exile in the ruins. It didn't matter whether that happened because of Undyne hunting him or because of Asgore going after him. 

It still stung though. 

Against all hope, he wished Undyne would succeed where the royal children had failed. He did not truly believe that she would, based on what he had seen falling into the dump. The humans had evolved weapons that even the brightest royal scientists barely understood, and old and soggy newspapers showed that they were no less violent now than they had been back when the prince and his sibling ascended to the surface. Stories of wars and murders had prominent places in almost all newspapers that ended up in the Underground. One monster wouldn't stand a chance against all of that in how opinion. But at the core of his soul sat the usual monster trifecta of love, compassion and hope, and he couldn't help but hold on to the thought that she might make it after all. 

They couldn't plan for that possibility with the lives of others on the line though.

“welp. guess we better get it over with,” Sans said. “let’s bring our stuff to the ruins and feed the baby first, so we're set no matter what happens.”

Papyrus nodded, indicating that he was ready. Their visit was quick and perfunctory, the baby slightly fussy. They seemed to sense something was off and we're unhappy when they got ready to leave quickly after cleaning and feeding them, their packed bags now stored in the living room. Sans brought them directly into the judgment hall as soon as they were done, and they knocked on the door to the throne room together. 

“Please enter,” Asgore called them. His voice sounded heavy, but otherwise normal. 

Bracing themselves, they entered the throne room and let the door fall closed behind them. 

“Howdy,” Asgore greeted them, his face friendly. “How can I help you two?”

“we’re here in our role as royal guard sentries,” Sans stated clearly, giving the king a meaningful look. 

All pretenses of friendly small talk immediately left Asgore's demeanour. He looked shaken and sunk into himself, looking at Sans and Papyrus with sad, pleading eyes. 

“You have information?” he questioned. 

“yeah. we, uh… well, my bro here and undyne are pretty close friends. and because of that, we got into a bit of a situation yesterday,” he began delicately. 

Asgore took Papyrus in and to Sans’ surprise, recognition sparked in Asgore's eyes. 

“You are Papyrus, are you not?” he asked. “Undyne spoke to me of a young skeleton monster she had befriended and employed. She has a very high opinion of you and your skills.”

Once more, Papyrus flushed, fidgeting under the scrutiny and praise of the king. Despite the fact that the palace door were always open to the populace, they hadn't been here before apart from some trips to New Home for some sightseeing. And while Asgore made the rounds as Santa over Gyftmas, they had not personally approached him either then, more focused on celebrating with each other. 

“yeah, that's him,” Sans confirmed. “i’m his brother, sans.”

“And you are both sentries?” Asgore questioned, taking a closer look at Sans now. It was clear that he wanted to make sure that the information about the soul would remain closely guarded for now.

“i man the first alert station in snowdin close to the ruins,” Sans confirmed, “as well as a second station in hotland. my bro has a permanent station in snowdin forest with the canine unit.”

“UNDYNE PROMOTED ME,” Papyrus blurted out, his first reaction to the nervousness that was clearly consuming him to point out his achievements. 

“Then I can assume you have been fully informed,” Asgore stated, “and know what is and stake. Thank you for coming forwards as quickly as possible. Please tell me everything you know.”

Papyrus glanced over at Sans and Sans braced himself. Being discovered by Undyne was one thing. Having to personally tell the king… that was a whole other league entirely. 

“a few months ago,” he said quietly, “i found the door to the ruins opened.”

He immediately caught Asgore’s interest, the king's head leaning forwards with interest. 

There was no point to talk around it now, so Sans decided to cut through the cap and come out with it right away.

“a human had fallen.” 

“I was not informed of this,” Asgore noticed. His statement was not accusing or angry for now, merely calm and factual. Sans didn't know what to think about that, whether to find that encouraging or unsettling. 

“no. i had made a promise to someone behind that door that i closely befriended even though we never saw each other, to protect any humans that came from the ruins,” Sans explained, noticing the king's interest increasing even more now. He supposed it was warranted, since such a promise was very unusual. 

“when i entered the ruins, i found the corpse of an adult human, and a living human baby,” he continued. He tried to get through this in a logical order, in an official way that befitted a sentry making a report to his king in a dire situation. Calm and collected, with little emotion for now. “it was unusual, but i was ready to take their soul before i remembered my promise. i closed the door and decided to search the ruins. inside, i found everything empty and devoid of life, the ruins covered in dust. i found the place where the human must have fallen. in a house directly before the entrance to the ruins, i found my friend’s diary, detailing how she had found the two humans fighting against a monster, and how the adult human had panicked and would not be soothed by her assurances that she wished them no harm. the human escaped her.”

Asgore was completely enraptured by his tale, a disturbed frown spreading quickly on his face.

“she intended to offer food to the human to prove her good will, but on her way through the ruins she found increasing amounts of dust. the human wasn't sparing anyone. she decided that she would try to stop them once more in her home before they could leave the ruins. this was the last entry she had made. i spread the dust of the fallen monsters on the roots of a tree in front of her house since i did not know them or their favoured objects. i buried the adult human at the place where they fell. i found her dust in front of the door to the ruins exit, in a room just before the human corpse. since i didn't know what her favoured object was either, so i spread her dust on the pages of her diary that mentioned our last interactions together. then i took the baby and began taking care of them, protecting them as per the only request my friend had ever made to me.”

He wanted to continue with Undyne, but he didn’t get the chance. Asgore was reaching out for him now, even though Sans and Papyrus stood too far away from him. 

“She is dead?!” 

Sans hadn’t expected that to be the thing the king focused on. He didn’t understand why the king suddenly looked so shocked and grief-stricken. The king was very compassionate, but this wasn’t just mere compassion.

“yes,” he confirmed, pulling the diary out of his hoodie pocket and opening it to the pages where he had spread the dust. “i searched the whole ruins but there was nobody left alive but the baby. based on her diary entries, the dust close to the doors of the ruins exit must have been hers.”

Asgore’s eyes immediately fixated on the pages, took in the tidy handwriting and the fine, unmistakeable shimmer of dust on it. 

And then he, Asgore, King of Monsters and Ruler under the Mountain, bent over in his throne and quietly began to weep.

“Asgore?” Papyrus asked. Sans could understand the insecure tone in his brother’s voice. He felt out of his depth as well, having no idea what to do now. Asgore was always such a bastion of kindness and strength for the monster to lean on and trust him. He was not perfect of course, he was still only a monster and made sure to show it, instead of trying to stylise himself into a flawless icon. But to see him like this, so broken and grieving, without even fully understanding why… it was a shock. 

“you knew her,” Sans said, not quite a question and not quite a statement. “i’m so sorry.”

Perhaps he shouldn’t have just spoken about the death so bluntly and formally. But how had he been supposed to know? His compassion compelled him to reach out and console the king. His paranoia flared, telling him this might be a trap, that Asgore was only pretending so he could grab them and force them to bring the king to the baby. But he waved the thought aside. Sans could be deceived, but his skill at reading people was still really good, and this was genuine. 

He stepped forwards together with his brother, and both of them placed a hand on one of Asgore’s shoulders. Sans could barely reach high enough, even though the king was sitting down. He could feel Asgore’s shoulders shiver and tremble underneath his armour. Asgore made no attempt to grab them, or even to move out of his hunched position. He merely cried into his hands, sobbing and dragging one ragged breath after the other, his pain palpable like glass shards in his throat.

“She used to be my wife,” Asgore eventually choked out, causing Sans to still in utter surprise once again. 

Every monster knew the story of the Queen in exile, how Asgore's partner had left him after what happened to their children. It was said that she went into hiding in exile, but it was never stated where or how. Many suspected that she too had died in the meantime, that the stories of her living unknown among the population were only tales to keep up the hope in the population. 

To think that Sans had befriended her, and via knock knock jokes and puns of all things… what a strange idea. 

And yet, it also explained so many things. Why she never showed her face, her old fashioned manner of speech, her lonely existence in a place that was supposed to be abandoned, and her fierce protectiveness towards children, even if these children were human. It made complete sense, but it still made Sans feel strange, to know that he had been one of the last and closest friends of the lost queen, that he had been the one to choose her final resting place even and was fulfilling her final wish. 

It took a long while for Asgore to calm down somewhat again. Even when his sobbing slowly subsided and he managed to sit up again, tears kept streaming over the matter fur on his cheeks and his eyes remained dark with sadness. 

“I… I apologise for my outbreak,” he said quietly. “I had always hoped that she might come back one day. Even if she never wanted anything to do with me again, I hoped I would at least see her. To hear that she is gone is a shock.”

“It's okay,” Papyrus assured him. “We understand. Sans lost a close friend with her, and I lost a different friend as well when it happened. We both had to come to terms with it too. It's hard when they die so suddenly. If you need someone to listen, we are here for you!”

He kept petting Asgore's shoulder, standing tall and sturdy next to the king. Sans was sad to hear his brother talk about his grief. At the same time, he was proud of Papyrus for offering his help so freely and in such a mature way even though the situation was so difficult. His brother was the coolest.

“Thank you.” Asgore stared ahead, not moving for a moment. He seemed to be lost, unable to decide what to do next, how to proceed. Sans understood that feeling well. 

“You said you began taking care of the baby?” Asgore eventually asked. 

He sounded tired. Tired and sad, and he made no effort at all to grab Sans or call for his guards or do anything else to hold or hinder them. 

“yeah,” Sans agreed. “hated it at first, but i couldn't not do it. by now… i love them.” 

“Of course,” Asgore said with a small sigh. “And if I were to guess, Undyne found out, about the baby and your feelings for it.”

“not hard to guess, huh?” Sans asked.

“No. She has a gentle soul underneath her fire,” Asgore replied. “I suppose that explains her drastic actions… she must have decided that this is the only solution. To do what I did not dare to do, and gather the last souls by herself. Thank you for telling me.”

“Will we be punished?” Papyrus dared to ask, voice insecure.

“By law I should be punishing you for withholding the last human soul and creating this situation,” Asgore said, though without conviction or anger. Sans still tensed, but Asgore apparently had other concerns. “Have you thought about what to do with the child?”

“raise them and protect them, whatever that takes,” he stated. It was perhaps simplistic, and he knew it left himself open to criticism and questioning, that he was admitting to all the potential problems. But it also told the king that he had thought about these problems and decided to go forwards anyway, and that was important to him. 

“I see. In that case, you should probably keep what you know quiet even from the other guards, and make sure that nobody else sees you leaving for the ruins when you return,” Asgore said. 

“SO YOU SUPPORT US?” Papyrus asked, immediately regaining his volume as hope spread over his features. 

“I cannot actively support you,” Asgore stated, causing both Sans and Papyrus to take a step back. “If Undyne does not return… how can I in good conscience leave the population in the dark for longer than necessary, when there is another soul that could help us in our quest?”

“THEY'RE A BABY!” Papyrus protested. 

“Yes. And believe me when I say that this causes me no small amount of grief. But so far, every human that fell into the underground has been a child. If I were to wait for adults only, we would not have gathered a single soul, and monsters would feel hopeless and die. If I support you there is no saying what will happen when the next human falls and turns out to be a child as well. I would not expect you to save one child but not the other. If I waited for each child to grow before I took their soul… they wished to leave. I would have had to imprison them. There is no saying what your child will want,” Asgore says. 

“And I worry about what might happen due to gathering souls directly on the surface,” he continues. “I initially worried that if I were to leave to gather more souls I might trigger a new war, or that if I failed monsters would lose hope and turn to dust, as they did after the death of my son. Now I worry about Undyne and what her actions might mean for us, even if she does return successfully. I can not say whether we would be able to withstand the power of the humans if they wished to destroy us out of revenge. Perhaps I worry too much, perhaps Undyne will succeed, proving herself better than any of us, proving me a paranoid fool who did terrible things for unnecessary reasons. I do not know. I am trying to do what I believe is best for my people based on my own convictions and experiences.”

It was hard to argue against that, even though Sans still wanted to, and based on his expression, so did Papyrus. 

“so what's next?” If Sans couldn't argue, he at least hoped that he could understand how things stood, what to prepare for. 

“We hope that Undyne returns, and soon.” Asgore was no longer looking at them, instead staring intently at his own furry hands. “We hope that she returns successfully before more monsters note her absence and learn of what she has done. We hope that I do not prove myself a fool by letting you leave this room instead of trying to restore what has been taken. We hope that no monster will dust as the result of Undyne’s decisions, her understanding and compassion… or mine.”

The hands clenched, the force behind the motion enough to make the muscles on Asgore's arm stand out. 

Sans decided to take that as his cue, and grabbed his brother’s arm. Just as Asgore looked up at them again, he took a shortcut out of the throne room and back into their home.

“THAT COULD HAVE GONE WORSE… RIGHT?” Papyrus was wringing his hands, sweat beading on his skull. 

“i suppose.” 

The truth was that Sans felt terrible. He had worried about the possibility of other monsters dusting too, and that’s why he had decided to tell Asgore. But now he wondered if it hadn’t been a mistake after all. They had gambled their own security out of compassion. Though that was what Asgore and Undyne had done too, so perhaps it was fair. 

“c’mon,” he told Papyrus, letting go of his brother’s arm to move over to their bags. He could only assume that Asgore was starting to prepare for the worst now, and so he felt he should do the same. “we should go ‘n prepare the ruins just in case. and take care of the baby.” 

He really hoped Undyne would come back soon.


	12. A true Hero

Days crawled by in agonising slow motion. 

Sans didn't know where he'd better stay, if he should take his brother and move permanently into the ruins, where they had already taken to sleeping, or if it wasn't better to keep up his regular life in Snowdin for as long as possible. Sleeping in the ruins gave them more time with the baby, who seemed increasingly happy and calm as they spent more time with them at night, but it didn't give them any additional rest. He and Papyrus were on constant alert, almost twitchy even when they tried not to be. They did go to their guard shifts, but they kept their sockets out for any sign of trouble, any ambush or whispered word that something was off. They hated being apart and Sans kept a firm grasp on his magic at all times, and an equally firm grasp on his cellphone at all times. Papyrus did too, and they both had their numbers entered and ready to dial, so they could bust each other out of trouble immediately. It still felt incredibly risky to be out and about at all, especially by themselves.

Sans occasionally dared to take a shortcut directly into the castle, hiding in alcoves or behind columns, to try and see if Undyne returned or of there was any news about the situation here. 

There was none. 

Whispers started to pick up among the population on the third day, that nobody had seen Undyne, that Waterfall was too quiet. Wondering if she was on vacation or sick or, and this was spoken of in only the most hushed whispers, if she had fallen down. Asgore called the guards to his castle during noon that day, officially for instructions. 

Papyrus and Sans did not attend, although Sans did take a shortcut to the judgement hall to listen at the door while Papyrus took care of the baby. 

Asgore explained to the guards that Sans was hiding a human child, and that Undyne hadn't been seen since she found out about it. That he did not know what exactly had been told to Undyne, to convince her of doing something so drastic. 

That he did not know how much of this situation was even real, and how much fabricated. 

Sans quickly returned to the ruins, where he and his brother had been feeding the baby during a break, when the commotion behind the door got too loud. 

He did not learn what the instructions to the guards were, how Asgore was planning to handle the situation to ensure no monster would fall down or die. 

“this is it,” he said simply, when he was met with the anxious eye sockets of his brother. 

“HE TOLD THEM?” Papyrus asked, desperate for it not to be true, even though Sans wouldn't pull a prank on him over something as serious as this. 

“a version,” Sans grumbled. “kinda left out the whole part where we confirmed that she stole a soul to go look for more outside. just told ‘em that she hasn't been seen since she found out about what we did. ‘n that we might have fabricated everything about her leaving.”

“BUT THAT MAKES IT SOUND AS IF WE DID SOMETHING HORRIBLE TO HER!” Papyrus pointed out indignantly. 

“i know.”

“WE WOULD NEVER DO THAT!!”

“i know.”

“HOW CAN HE DO THIS TO US? WE'RE NO CRIMINALS!”

“i hate it too,” Sans sighed. “but i understand why he said it. now everyone is angry rather than sad. and they have a goal, to break through the door to the ruins and catch us, to get the soul. it means it's less likely that monsters will fall down from this. it's clever…”

“IT'S RUDE AND DISHONEST!” Papyrus insisted. “YOU SHOULDN'T DEFEND HIM!”

“right, sorry,” Sans said, sitting down next to his brother. “in any case that means we gotta stay here for now.”

“WE… HAVE EVERYTHING WE NEED, DON'T WE?” Papyrus asked. 

“think so. clothes, food reserves including milk, personal mementos, my petrock and some of my equipment, your computer ‘n action figures… “ Sans thought out loud. “should be all. if you have anything else you want me to fetch though we should probably hurry. won't be long before they get to our house.”

“NO, I DON'T WANT TO RISK IT.” Papyrus looked dejected. Sans knew there was some stuff they had left behind that Papyrus would love to retrieve, such as the TV and his MTT movie collection. But the TV was bulky to transport even with the help of Sans’ shortcuts and difficult to connect here in the ruins, and without it the movie collection was useless too. 

“i’m sorry, pap.”

He wasn't sure what he was apologising for himself. His failure to bring back the TV? Accidentally taking Undyne along? Involving his brother at all? Maybe it was all of these. He wanted so badly for Papyrus to be happy, instead of being stuck here in the ruins. 

His brother's hand on his back startled him out of his dark thoughts. 

“IT'S OKAY, SANS. YOU MADE YOUR CHOICE AND I MADE MINE AND NOW WE'RE BOTH HERE! PROTECTING THE BABY LIKE FAMILY!”

“yeah. you're right, paps.” He had to remind himself of that; that his brother was a capable adult and had ultimately made his own decision. He could have decided not to support Sans, to try and help Undyne. Sans had wanted Papyrus to like the baby, but he certainly hadn't pressured his brother into going into exile with him. 

“OF COURSE THE GREAT PAPYRUS IS RIGHT!” his brother insisted, beaming down at him. 

In his arms, the baby was imitating the wide smile, showcasing the two tiny teeth on the bottom of their jaw that were barely breaking through their soft gums. 

A warm, gentle feeling resonated through Sans, suffusing his bones. He felt supported and protected, but also a strong urge to support and protect in turn. 

He moved closer, careful not to jostle his brother's hand on his back, and leaned against him. Papyrus felt sturdy and safe. He reached out and allowed the baby to grab onto his phalanges. 

No words needed to be spoken. Sans knew that the message would get across. How much he loved his brother and appreciated his support. How glad he was, that he didn't have to go through this alone. Even the baby, though far too young to truly understand his situation, seemed to get that this was an intimate and loving moment. They made no sound and just held on to his phalanges, smiling up at him. 

They were always so happy to see him now. Papyrus too, but they looked at Sans as if his sorry mug was the sun itself, a miracle gracing the underground, the best damn thing they would see all day. Papyrus had looked at him like that too, once, when he was still a babybones. 

It was overwhelming and scary and completely wonderful.

“DO YOU THINK WE SHOULD GO AND CHECK THE DOOR?” Papyrus wondered, startling him out of his pensive thoughts. 

His brother's voice seemed even louder than usual in the utter silence of the ruins. 

“nah. the door has held up for centuries no matter what anyone did. lotta people tried ‘n nobody ever made it through. if someone manages to break through that then nothing we could add would make a difference,” Sans explained. 

“OH. WELL, AT LEAST IT'S A VERY STABLE DOOR THEN,” Papyrus said, a nervous undertone creeping into his voice nevertheless. 

“yeah.”

This would be a reality of their life here, Sans realised, the constant low key paranoia about someone getting to them. Had _she_ felt like that while she was here? The former queen, Asgore's ex. He still had trouble wrapping his mind around that. The fact that the house sat right on top of the exit made it no better. He had the irrational desire to destroy the staircase and collapse the corridor, even though that would be dumb. It would only threaten the structural integrity of the house, and he already explained that for someone who managed to break through whatever it was hat made the ruins door so impassable, additional barricades would be merely a brief nuisance at best. 

“wanna go to the flower patch?” he suggested, wanting to get away from the proximity of the door in spite of everything. 

“YES, LET'S.” 

Judging by the relief on Papyrus’ face, he was just as eager as Sans to get a bit of distance between them and the door, to take care of his friend’s grave and distract himself with puzzles, at least for now. 

They were quick to get ready, Sans entertaining the baby while Papyrus gathered the watering can and filled it. On the way through the many corridors and puzzles of the ruins, they were quiet, only occasionally indulging the baby when they pointed at a plant or lever, babbling. 

The flower patch had grown a little under Papyrus’ care, the wilted flowers regaining their strength with a new steady supply of water. Papyrus was meticulous in this as he was in everything else in his life, and always made sure that he got every single flower, that all the corners were included. Then he did the same for the grave of his flower friend, directly next to the patch. There was a sparse, pale bit of green growing on the little mount, giving hope that perhaps, the resting place of Papyrus’ friend would eventually be covered in blooms or at least a bit of green as well. 

Despite everything going on, it was nice to see this little bit of growth. 

It seemed hopeful somehow. 

After watering the graves, Papyrus took a moment to reflect, staring at the grave. Sans felt for the diary in his hoodie pocket, tracing his phalanges over the spine. 

Two good friends lost, and now he and his brother tried to draw strength from what they had left behind. 

Sans had already been forced to find so much strength in the aftermath of losing his own friend. The baby had made it necessary. Now that he would live permanently in the ruins, he wouldn't be torn between two very different lives anymore, trying to split his time and attention between two important things at once. Perhaps he could see it as a sort of new start… 

Papyrus was drawing himself up as well. Puffed his chest out and set his face, strength and the full force of his will evident on his features. His brother looked more mature than ever before like this, and Sans couldn't help feeling a sort of bittersweet melancholy; his brother had been an adult for a while now but Sans felt that in the aftermath of accepting the baby into their lives, they had both grown up more in different ways regardless. And despite the fact that he would have loved to spare his brother the grief, the pain, and the difficulties they were now in, he couldn't help but feel proud of his brother. Proud of the man he had become. Papyrus was such a good guy, strong and kind, moral and understanding, passionate and funny. It gave him hope that maybe, just maybe, the baby would turn out alright too, despite the adverse circumstances. After all, having such a cool guy to look up to, how could they not turn out alright? It was impossible. 

“WE SHOULD PROBABLY GO BACK,” Papyrus decided. He looked ready and emboldened. Whatever had gone through his head as he stood there at the graves, it must have given him new motivation. 

“Anabababa!” the baby gurgled. 

“ok. wanna take the long way or a shortcut?” Sans asked. 

“WE SHOULD PROBABLY TAKE THE LONG WAY. NOW THAT WE'RE GOING TO LIVE HERE, WE SHOULD START TO GET FAMILIAR WITH THE TERRITORY SO WE KNOW IT LIKE THE BACK OF OUR HANDS!” 

It was something that he clearly learned from Undyne, something that she would have said if she were here. It was a good point though. They needed to be able to find food in the ruins, and when the kid grew older, they would have to be able to make sure they were safe walking around in the ruins, so knowing the territory was paramount. 

“ok. then let's go.”

They made their way back through the long corridor leading away from the flower patch, back the way they came. The darkened room where Sans had found the slashed flower loomed before them, the single bright spot of light illuminating it the only guide through the darkness. Behind that, Sans knew that the first puzzle was waiting, knew roughly what awaited him in terms of rooms and staircases and corridors… 

An empty, quiet ruin of a city, nearly abandoned for centuries, now so close to entirely empty. Their echoes would be the only sounds in this place from now on.

He felt as though he wasn't just stepping into the ruins. He was stepping into what would be his quiet, new life from now on. 

His brother seemed to understand the significance too, smiling down at him when he looked up. The baby was babbling happily in his arms, reminding them of their motivation for this chosen life.

Together, they stepped forwards into the darkness, towards the light. 

_Boom._

“Aaaaaah!”

“WHAT WAS THAT?”

“dunno. shh.”

Sans began rocking the baby, hoping to silence them. They were squirming in his arms and whimpering at the sudden noise. The sound was echoing throughout the ruins, loud and multifaceted; impossible to determine from where it had originated, especially since his brother and the baby’s loud shriek had covered the initial echo. 

A deep sense of unease crept over his bones, quickly transforming into fear. 

Had the door been broken after all? Were they discovered? Would all his thoughts about a new life in this place turn out to have been for nothing? 

Steps. 

There were steps sounding from behind him, heavy and approaching fast. 

His head turned, but he couldn't find his brother's sockets in the dark, not having made it towards the patch of light yet. He didn't dare move, what if they were heard? This was the place were humans fell. All humans so far had come from the ruins and this was where the only big opening could be found in the cave ceiling here as far as Sans had been able to discover. With him carrying the baby, the human might think he was an abductor or worse, he knew he looked like a human corpse and he was a monster, surely they would -

The steps came to a stop right behind them, a large, hulking figure appearing silhouetted in the door frame. 

Too late to try and sneak away. 

Sans gathered his magic, could see his brother do the same out of the corner of his eye sockets, and they both readied themselves to fight. 

Only to stop as bright cyan magic sparked over the body of the figure in front of them, briefly illuminating features they knew all too well. 

“UNDYNE!!” Papyrus shouted, relief clearly audible in his voice. 

“Who did you think it was, you nerd?!” she asked back impatiently. 

“a human,” Sans grumbled, the shock of relief cursing through his own body making him angry. 

“Fuhuhu. There are certainly some human things inside of me,” Undyne promised with a wide grin. Her teeth glinted in the sparks of cyan magic her body gave off, sparks that seemed to appear uncontrolled.

“YOU DID IT!?” 

There was no need to clarify what he meant. 

“Of course I did! Did you doubt me?” her laugh was wild and almost carefree, echoing through the empty rooms and corridors surrounding them. 

It was surreal. 

Sans seriously asked himself if he was dreaming, not ready to simply believe this was happening. No matter how much he blinked or questioned his surroundings though, the image remained true. 

“I WOULD NEVER DOUBT YOU! I WAS ONLY A LITTLE… WORRIED?”

“That's the same thing!”

“IT'S NOT! RIGHT, BROTHER? ...BROTHER? SANS!”

“w-what?” He couldn’t stop staring at Undyne. At the crackling magic that gave just enough faint light to get an idea of her expressions and her body, gone to fast to see it for real. Even so, something seemed… different, about her.

“Are you okay?” 

“i feel like i’m dreaming,” he blurted out. 

“Why is everyone acting as if I couldn't have done this?!” Undyne complained. 

“WELL SO FAR NOBODY EVER DID IT!”

“I'm not nobody though?!”

Their bickering carried on and Sans suddenly began to laugh. 

It started as a snort, almost a hiccup, before it grew into a chuckle and then drawn-out, full-blown laughter. His eye sockets stung, but no tears came. Instead he felt a sudden rush of giddy excitement that he hadn't experienced in a long time. The feeling was almost as surreal as the situation itself.

“What's so funny?” Undyne questioned. 

“you made it,” Sans said, almost sounding weak with all the emotions coursing through him. 

“Hell yeah!” Undyne hollered. “Saved your kid and everything! And the whole monster population! No big deal.” And she cackled, as if it really wasn’t, as if this was nothing bigger than her usual Tuesday morning jog.

“we’re safe?”

“You're safe.” 

“WHAT WAS IT LIKE ON THE SURFACE?” Papyrus asked, his curiosity clear in his voice. He almost sounded like a child again, innocent and waiting for wondrous stories of a place as unreachable as a faraway universe.

It was only then that the full truth hit Sans. He had been so preoccupied worrying about the kid that he hadn't thought about much else, even now that Undyne returned. But now with Papyrus’ question, it was clear to him. 

She had managed to gather the final soul they needed in order to be free. 

They were _free_. 

“Oh man,” Undyne said. She sounded awed in a way he had never heard from Undyne before, her voice still enthusiastic but softer and a little more vulnerable as she allowed the full impact of what she had seen to shine through. No concern about trying to maintain her tough image. Only overwhelmed joy. “Oh man, it was… it was great. You're going to love it. It's huge! You can look so far and you're outside - you think you're outside now, but you're still in a cave! You don't know what outside _means_ until you've been up there! And it’s so bright?! The sun! And the night sky! There was so much to see I got a headache at first! You can feel the wind, and hear birds and all kinds of funny animals, and there’s so many humans and buildings ‘n shit… that was scary. But also really cool. I wanna go back again like yesterday!”

Sans was staring at her rapt with attention, taking in what he could see of her outline, of the crackle of magic that still burst from her hands and occasionally her face. His sockets were wide open and even his mouth was hanging open a little. The surface had always been such an abstract, far away concept to him. Not something he genuinely expected to see during his own lifetime. But now here was one who had seen it, and returned to tell the tale. And they would go there. All of them, together. Monsterkind back under the sun at last. He suspected that his brother's face must likewise be filled with innocent wonder. Nobody could hear this, understand what this meant and not feel as though a miracle was happening. 

He suddenly wanted to see Papyrus clearly, and Undyne too, get out of the darkness and properly look at his brother and his brother's friend, the final proof that this was not some bizarre dream his mind was presenting to him as real. 

“we should go and tell the others!” he suggested, not quite able to hide his own hope and excitement. He couldn't recall ever having sounded like this, it felt strange. At the same time, he didn't care. The prospect of seeing the surface, while simultaneously knowing his child was safe at last, was enough to give him an energy and enthusiasm that he would usually consider more appropriate for Papyrus. 

“Wait,” Undyne stopped him. “What happened while I was gone? Did everyone make it?”

“i’m not sure, but i think so,” Sans replied, wishing he could give her better news. “we’ve been kind of cooped and keeping away from everyone. ‘n today we’ve spent entirely here.”

“Because you’ve been found out?” Undyne guessed. 

“we told asgore the truth. thought it was better if he could prepare properly, to make sure nobody falls down. he, uh, decided to put the blame on us fully to motivate the population, so we skedaddled out of there,” he explained, keeping a flippant attitude. He wasn’t exactly happy about what had happened, but he still understood the motivation behind it at least and with freedom looming, he was ready to let it go. 

“What do you mean, put the blame on you fully?!”

“asgore said some things that made it sound as if we’d done something to you and then faked your letter and other evidence of you going to the surface,” Sans sighed. “but look, it - “

“I can’t believe him!” Undyne fumed. “Why the hell did I even bother to write that letter?!”

“if you hadn't come back and he said the truth, monsters would’ve died,” Sans said bluntly. 

A growl made it out of Undyne’s mouth, half wordless and and half exasperated mumbling. She was clearly pissed that she had been doubted, but she was also experienced enough to understand why it had happened. 

“BUT YOU'RE BACK NOW,” Papyrus stated in a clear bid to brighten the mood. “SO WE CAN JUST LET EVERYONE KNOW WHAT REALLY HAPPENED AND WITH YOU TO CONFIRM IT, WE CAN LET BYBONES BE BYBONES!”

“Fine, whatever,” Undyne grumbled. It was pretty clear that for her, the issue wasn't over yet, but she seemed.to be ready to let it go for now to focus on the more important stuff. 

“so i’ll take us to the throne room?” Sans asked, the excitement in his ribcage not having abided even with the sudden darker topic.

“Yeah,” Undyne confirmed. “Just don't freak out once we're there.”

“WHY WOULD WE FREAK OUT?” Papyrus wondered. 

Sans had a hunch why, but Undyne had turned towards him and clearly didn't want to elaborate. So he focused his magic, reaching out with it to make sure they were all included in the shortcut, and took them to the throne room. 

They appeared right in front of the throne, startling Asgore and three of the guards who appeared to have been in a discussion together, 01 and 02 as well as Knight knight. Under usual circumstances, Sans would have been worried about himself, his brother and the baby, suddenly being surrounded by the king and several guards. Especially since the baby was obviously shocked by the sudden change of scenery and the people in the room, flinching in his arms and hiding their face in his hoodie. He automatically began rocking them and muttered calming things to them. He wasn't quite worried though because nobody had eyes for them. 

Everyone was staring at Undyne. 

Even himself. 

She had always been tall, but she had grown. With the power of two souls inside of her, it was already abundantly clear that she was not a normal monster anymore. Her teeth and claws were longer and sharper. Her eye patch was gone, the empty cavity usually hidden behind it unnaturally dark except for the bright spears of cyan magic that kept flashing out of it in irregular intervals. Her hair was waving in an unseen wind, moving independently of any drafts or other forces surrounding them. Magic crackled not just in her left eye, but also on other parts of her body - on her fists, through her hair, over the plated armour she wore. Armour that had apparently transformed with her, the simple and functional plates gaining elaborate, heart-shaped decorations, a faint shimmer of colour visible on the darkened metal, like oilslick under light. 

“Undyne,” Asgore said, completely disbelieving and at the same time soft and hopeful, loving. 

In response she drew herself up and met his gaze with fierce determination. 

“I've done it,” she stated, her voice echoing through the throne room. It occured to Sans that the echoes he noticed now and earlier were just as unnatural as her new height and her flowing hair. It was a resonance of power, not a result of her surroundings. “I have ascended to the surface and gathered the last soul we needed to break free of our prison! No innocent has been harmed by my actions - not the baby Sans was protecting, not the monsters bereft of hope in my absence as far as I have been told, and not the human whose soul I took. I waited for my moment, chose a criminal about to commit a horrendous crime on another human, and brought justice upon them! The humans cannot fault my actions after I saved one of their own from harm! There should be no threat of war, no danger hindering our escape. The time has come to break out of our prison! Will you give me the other five souls, so I can shatter the barrier and free monsterkind at last?”

It was an impressive speech, made even more impressive by the fact that Sans knew Undyne had improvised it. She always did, because she constantly forgot the ones she prepared beforehand. 

Asgore and the other guards were all staring at her. The guards were moved to tears, their expressions heartbreakingly happy and hopeful. Asgore's face was more somber in comparison, not quite grief but a sort of bittersweet melancholy. 

“If you absorb these souls,” he said quietly, while his voice was still clear enough to be heard throughout the room, “ there is no going back. You have already changed much and with the other souls inside of you, you will be nothing like before. Are you willing to sacrifice your body and identity for this matter?”

“Pff, I've already changed this much, I'm not gonna stop now!” Undyne challenged. 

“I am serious - “ Asgore began. 

“So am I!” Undyne seemed to have no trouble interrupting him. That was par for the course with her when it came to anyone else, but based on what he knew of her relationship with Asgore, it was unusual now. “I didn't go out there knowing I might die or end up doing something terrible just to get that last soul only to give up now! I knew what this meant and I was willing to stick it out! Come on, do you seriously want to stop me now?! We're so close!”

“Of course I do not wish to stop you,” Asgore sighed. “I merely worry about you… but I suppose it is already too late for my concerns. You are right. Your choice has been made the moment you left. Come. Let us go to the barrier.”

He gave only a brief glance at Sans and the baby before he turned towards the end of the room, where the corridor leading to the edge of their world began. The guards followed his gaze with curious eyes and Sans tensed for a moment, suddenly afraid that they might decide to harm the baby after all for some reason. But they simply regarded them with the kind of curiosity that was a natural consequence of not having seen a human ever before. Only Asgore lacked it, and he showed no aggression either. 

Following Asgore, Undyne and the guards through the corridor felt surreal to Sans. He kept expecting to wake up from a dream, even when he did everything he could to make sure that he was aware and sound of mind. Soothing the baby, exchanging glances with his brother, noticing the smell of stone surrounding him and the feeling of clothes on his bones, the background sounds of rattling armour and gravel scraping under boots. Little details that never quite made it into his dreams. 

These sounds were quickly overtaken once they entered the final room of the castle, by a sound so low and hollow and rustling that it appeared like the breathing of a living creature as vast as the earth itself. Even the baby looked up at the change, no longer whimpering or hiding. Their eyes were wide as they took in the scenery. Sans felt his body tingling under a great pressure, the feeling of magic so potent that he thought he might choke on it. 

The barrier was before them. 

Asgore drew seven containers out of the floor. Sans wasn't entirely sure if they had been hidden by a mechanism, magic, or both. Two of the containers were empty, the other five contained souls in a variety of colours. He couldn't feel them inside these containers, but it still seemed odd to him, to have something so intimate and vibrant as a soul be kept inside glass and steel.

“Are you ready?” Asgore asked, his voice echoing inside the room, against the deep sound of the barrier, twisting ominously. 

“Yes.”

Asgore stepped back, and gestured to the containers. It was apparently all that was needed, because the containers opened at once and Undyne stepped forwards, spreading her arms and drawing the souls into herself in a flash of magic. They followed the bright cyan bolts of power, circled her for a moment, and then sank into her chest. 

Sans wanted to keep looking at what happened, wanted to take this moment in and commit it to memory forever, but he couldn't. A blinding white light radiated from Undyne's body as soon as the souls entered her, forcing his eye sockets close. He managed to press the baby close to his chest, covering their head wish his hand to ensure they wouldn't be blinded. He heard a roar, Undyne’s voice magnified in pain and then triumph, increasing in size and volume until it rivalled the massive scale of the barrier itself. 

A sound like the shattering of glass rung throughout the room, perhaps throughout the entire Underground. The pressure vanished.

His eye sockets opened slowly. 

For the first time in his life, he saw unfiltered sunlight, shining down the corridor in front of him. He felt a faint draft moving against his bones. Something in the air changed, a smell of forest, of bark and pine needles, that was fresher than the familiar smell of Snowdin. Birds could be heard singing, and a faint scent of blooming flowers made it to his nasal bones. 

The baby cooed in his arms, reaching towards the light with their small hands in a clear desire to approach that needed no words.

Sans stepped into the light without thought.


	13. Epilogue

**Notes for the Chapter:**

> Well, here we are. This is my first ever finished multichapter story. I have too many emotions to properly express them right now, but above all I hope that you'll enjoy the ending. 
> 
> Thank you so much for reading and following this story, and for supporting me while writing it.

It was a beautiful day. 

The sun was high in a sky dotted here and there with fluffy clouds, a faint breeze rustling the trees and the grass every now and then, ensuring that it wouldn’t get too hot. Summer had already begun, but the true heat hadn’t settled in yet. That would still take a couple of weeks - for now the weather was pleasantly warm and dry. 

The sounds of the city were fading here, barely audible over the little noises of the breeze, over the dogs barking and playing with their owners, the happy shouts of a small group of children playing not too far away.

Sans leaned back on the blanket he was sitting on, feet going over the edge and resting in the grass. He could feel the individual blades tickling his tarsals and metatarsals, making him grin. When he took a deep breath, he could smell mown grass and apple trees, and the dusty smell of the gravel path leading past the lawn of the park. 

“really cleared up over the past week,” he commented, idly watching the different signs of the changing weather. 

“IT DID! IT'S VERY NICE OUTSIDE, ALTHOUGH I LIKED IT WHEN IT WAS RAINY TOO. THE RAIN IS SO DIFFERENT UP HERE!” Papyrus immediately agreed. 

The weather might have been a boring topic of conversation for most humans, but monsters tended to discuss it with great enthusiasm and fascination still. It was so different from what they were used to in the Underground. 

Everything was different here. 

“DO YOU THINK SHE'LL COME?” Papyrus asked, preventing him from thinking too much about the many, many differences between the surface and his old home. 

“dunno, paps. she's pretty busy.”

“SHE'S ALWAYS BUSY AND I HAVE A LOT OF UNDERSTANDING FOR HER BUSINESS BUT WE ARE ALSO REALLY BUSY AND IT WOULD BE _VERY_ NICE IF SHE MADE IT,” Papyrus stated, rather forcefully if still polite. 

“that's true, but ya can't compare our jobs and hers,” Sans pointed out. 

“WELL!! THAT… IS CERTAINLY ACCURATE,” Papyrus conceded. 

His voice was a mixture of greatest pride and a little bit of jealousy that still hadn't quite faded, which Sans could understand. ‘The Great Papyrus’ was an awesome title, especially when it had been made official as Papyrus was invited to assume the role of ceremonial head of the royal guard and part-time ambassador to humanity. He had been knighted with a ceremony and everything, tasked with organisation and motivation of the guardsmen, which he did very well. He was a natural.

But the title did pale just a tad in comparison to ‘Undyne the Undying, God-Empress of the Undergorund, Angel of the Prophecy and Liberator of Monsters.’

“she'll try i’m sure,” Sans tried to reassure his brother, who sighed quietly and shifted around on the blanket, glancing at the baskets and their gear. 

They had brought some premade food and some to prepare here, since they also hauled the grill out to the park, hoping to have a small barbecue together with everyone. Undyne had been invited, Asgore, Alphys, who might bring Mettaton, some of the guards… they were all busy people though, so worst case scenario they'd be by themselves. The food would get eaten, that wasn't the problem, but it was nice to get the group together for some time to relax among family and friends. 

“IF SHE DOESN'T MAKE IT,” Papyrus decided, “I'LL HAVE TO HAVE VERY STERN WORDS WITH HER. IT'S NOT HEALTHY TO WORK THAT MUCH!”

“Who are you going to have stern words with, huh?!” a gruff voice spoke up right behind them. 

Sans flinched a little and turned, Papyrus jumped two metres into the air and screamed like Mettaton did when he first saw the evils of fast fashion. He was so loud that even the other visitors in the park turned their heads and looked over in surprise, nearby couples walking their dogs and the group of kids playing football a few paces away. Most of them laughed when they saw Papyrus squawking, with Undyne breaking out into roaring laughter behind them. 

“You gotta work on your vigilance,” she cackled, wiping a stray tear away from her eye. 

“IT'S NOT FAIR WHEN YOU USE YOUR POWERS TO CHEAT!” Papyrus accused her. 

“Pff, I've always been good sneaking up on people, don't try to weasel out of this!!” she declared. “I'm not even letting it all out!”

For a second, Papyrus and Undyne glared at each other, the grins on their faces challenging. Then they couldn't pretend anymore and both started laughing again. 

“heya,” Sans told both of them, himself not able to conceal that he was happy to see them. 

“YOU MADE IT! I REALLY HOPE YOU WOULD,” Papyrus told her, beaming at her and then at Asgore, who was slowly walking up behind her. 

“Yeah!!! I finally sealed the deal on the accessibility laws, so I got the rest of the day off,” she boasted. 

“oh, did they finally see reason?” Sans asked with a raised brow bone. 

“Yes,” Undyne replied with a sharp grin. 

“She gave them that look again,” Asgore explained in a slightly irritated tone, having reached their group now. “And let me deal with the rest.”

“You do make for a perfect good cop in that routine,” she praised him, _very_ gently clapping him on the back. 

“I wish you would not frighten them with your power,” he sighed. 

“Well they were being stupid about it,” she grumbled. 

Sans caught her eye and she winked at him, causing him to snicker at her antics, which only made Asgore sigh more. Sans couldn't help it though, he didn't quite like the human authorities. Objectively Asgore was right, and it would probably be better if Undyne had used a more diplomatic approach. But he was still grateful to her for all her help, everything she had done for him… and he knew from experience that sometimes it could be a good idea to let the humans know that they weren't just dealing with any old random monster. 

They were dealing with someone wielding the power of a god. 

Undyne might look perfectly normal right now, her body appearing exactly as it had before the whole thing with her trying to gather the last soul started. But everyone knew what was truly hidden underneath. Undyne had learned to control her power to the point where she could decide what her body looked like, could push her magic into assuming the physical shape she desired for herself. In spite of everything, she still preferred her old looks, and that was how she appeared. 

Initially though, she hadn't known how to do that. So when the monsters emerged from Mount Ebott and first established contact with the humans, the authorities had been met with a hulking, gigantic _beast_ of a monster, one with too many twisted limbs with sharp claws as long as swords, spouting out of a torso that seemed to consist of solid, brightly gleaming iridescent metal, hair that appeared to be made of plasma waving with heat and power, and a huge pair of wings inverting and extending in ways the normal eye wasn't meant to perceive, darkness mixed with pale shifting colours visible in them that hinted at something so out of this world that there were no words to describe them. 

It turned out that even the humans with their terrible weapons were somewhat cautious when faced with something like _that_. 

Especially when this seemingly incomprehensible entity crouched down and, with a voice whose sheer power and presence seemed to resonate out of the universe itself, politely asked about the best way to immigrate. 

They had been so baffled that nobody ended up attacking her, and once the first fragile thread of contact and communication was established, many humans had apparently decided that challenging a species with something like that as their leader just wasn't worth the trouble, not when they were so willing to be peaceful as long as they weren't attacked themselves. She couldn't bank on that forever of course, but there some humans who were still a little intimidated by her and might cave if she presented a tough front while Asgore presented reasonably worded semi-compromises in their favour. 

“Anyway, the important part is that it worked out,” Undyne decided, parking her bony butt on the blanket next to Papyrus. “Are we really the first to arrive?!” 

“surprisingly enough, you are,” Sans confirmed. “alph’s writing a thousand page novel on whether or not she should come again, but after the last fifty three redecisions her last post stated that she'd try to make it, so.”

“If she doesn't show I'll go and carry her over personally,” Undyne pouted. “I made time and everything.”

“YOU COULD WRITE HER AND LET HER KNOW THAT YOU'RE ALREADY HERE,” Papyrus suggested with a waggle of his brow bones. He was always quite invested to get Alphys and Undyne to interact more. There had been a bit of a break between the two when Undyne had found out about the determination experiments and the amalgamates after her coronation, but they were approaching each other again quickly and Papyrus was helping them wherever he could. 

“You write her!” Undyne decided, only to immediately change her mind. “No wait, I'll do it myself!” 

She pulled his cellphone out of his hands, leading to him complaining why she didn't use her own. While the two of them pretended that their bickering was serious, Sans got up and shuffled over to Asgore, who had gotten the grill started. 

“need any help?”

“Perhaps you could begin to unpack the food,” Asgore said after a brief moment of thinking it over. Sans got started without complaint and by the time he was done, the grill was heated up and ready to go. They divided the food up between them based on experience without needing to talk about it; Asgore went for the vegetable skewers and baked potatoes, Sans for the hot dogs and hamburger patties. It felt rather companionable. 

They had needed a while to get to this point after what happened in the Underground, but Asgore had made a complete turn as soon as the monsters were freed. Especially after the population had clamoured for Undyne to become their new ruler immediately after learning how she had taken initiative to free everyone. She had been insecure at first, but Asgore surprised her by agreeing with everyone else and abdicating willingly. He offered his services to her as an advisor based on his long experience with ruling, but otherwise kept away from any positions of power or importance. 

He went into social work and volunteering instead, working long hours to improve the situation for monster children and later also for human kids once the authorities let him and he had been able to get certified properly. The humans hadn't been told about that part, but for the monsters it was pretty clear that this was his way of atoning for how he had handled the situation with the children who fell into the Underground. 

Which in itself maybe wouldn't have been enough to sway Sans’ personal opinion, but Asgore also made a strong effort to support Sans when the child services caused trouble for him, insisting that a monster couldn't properly take care of a human child. Things got tense for a while, and Sans was more than aware that without support from someone who knew more about the care of human children than he himself did, he never would have been able to pass the checks by the agency. He still had to comply with regular home visits even now, but he was no longer in direct danger of having his kid taken from him. 

The adoption had finally gone through half a year ago. 

Initially, they had all wanted to know where the kid had even come from. That was one thing Sans had been able to agree on. He had been curious about their origins too. The police investigation had finally turned up results after months and months of nothing - a mother who had died in childbirth, leaving a father alone with the baby. Both of the latter had vanished without a trace, but it had taken long before anyone noticed since they didn't have any other close relatives or friends. The father had been known for his gambling debts and short temper throughout the neighborhood, and most of the neighbors avoided him completely. The police suspected he had planned to commit suicide with his child when taking care of a baby by himself had become too much for him on top of his fresh grief and everything else. Sans felt ambiguous about this person; on one hand understanding their plight, on the other unable to forgive the one who had robbed him of his closest friend.

More importantly though, this had finally given him a name for the kid. 

He wasn't the biggest fan of the human who had killed his best friend, but he still decided to keep the name, as a connection to his kid's original heritage. He didn’t know if the mother or the father had chosen the name, and besides he felt that it wasn’t his place to judge or forgive them. That was for the kid.

“i think these ones are done,” Sans declared, using a fork to pull the water sausages and hamburger patties off the grill and onto the hot dog and burger buns. 

“The vegetables still need a bit longer,” Asgore declared. 

“I want a hamburger!” Undyne yelled, apparently having listened closely to their conversation. 

“sure. extra cheese?” He barely waited for her confirmation before he piled the cheese up on her burger. 

“Hell yeah!” Undyne made grabby hands at the plate and pulled it out of his phalanges as soon as he handed it to her. 

“I'LL WAIT FOR THE VEGETABLE SKEWERS,” Papyrus said, which Sans had expected. 

So he turned to the side instead. 

“hey! food's ready!” he called across the lawn. 

The effect was instantaneous. The children playing on the lawn broke up their football game, and began running over to him, one far ahead of the others. 

Knowing what was coming, he opened his arms and braced himself, just in time for when the impact hit him square in the chest. 

“oof! careful frisk, you’ll make me fall into the grill.”

“Dad! I got five goals! Five!” Frisk told him excitedly, completely ignoring the warning about the grill. They were a little out of breath and their cheeks were reddened from the exertion, their hair mussed up. He didn’t even bother to try and straighten it out, that was always a lost battle with them. They were also lisping a little, having recently lost their first front teeth. 

Because apparently humans agonisingly grew a whole set of teeth over the span of several years, only to then regrow from the ground up shortly after. 

Humans were _weird_.

“that's a lot,” he replied, grinning down at them with pride. He gave them a nuzzle and they pretended to be terribly embarrassed by it, because they were a big kid now obviously, but in truth it took them less than a second to nuzzle him back full force. “well done, kiddo. ya must be hungry after all that, do you want a hot dog or a burger?”

“A hot cat,” they giggled, their eyes hopeful and cheeky at once. 

“heh. ok.” 

“In a toasted bun!”

“your wish is my command.”

“And extra ketchup!”

“just like your old man, huh?”

“Yeah!!”

Chuckling, he turned back to the food when they let go of him, starting to get it ready. By now the other three children had arrived too, Monster Kid, Diamond Boy, and a human named Charlie, clamouring for hot dogs and burgers and shouting their condiment and topping preferences at him. With years of experience as an illegal hot dog seller and then as a father, he filtered the cacophony into individual voices and got everything ready as demanded, handing the plates out as fast as he could get them ready. 

Frisk's was special, their sausage cut into the shape of a long cat and drowned in ketchup, just how they liked it. The poor salad underneath soaked through; it didn't stand a chance. Nor did the food itself once they got their grabby hands on it. They practically inhaled the food and for a moment he wondered if he'd have to pull the plate away from them lest they'd eat that too. 

“More?” 

“take one of fluffybun’s vegetable skewers,” he told them, finally having gotten around to his own hot dog. 

“Can't I have both?” they pouted. 

“first the veggies, then the second ‘dog.”

“Cat!”

“or cat,” he allowed.

They ended up eating not only the vegetable skewer and another hot cat, but also shared a baked potato with him.

“no idea where you put all that food,” he marveled, poking them in the side. 

“In my big kid body!” they insisted, lifting up their arms to flex. 

“Yeah!!! They need it to build muscle!” Undyne laughed, joining them and doing a flex of her own. Of course Papyrus wasn't far behind them. 

“AND IT'S WORKING!” he boasted. “NOT MUCH MORE AND YOU'LL HAVE CAUGHT UP WITH THE GREAT PAPYRUS HIMSELF!”

Frisk beamed at the attention.

“Will I grow as big as you, papa?” they asked.

“WHO KNOWS!” Papyrus stated, and looked over to Sans. Paps may have learned a lot about humans and took care of Frisk just as much as Sans did, but Sans was still their dad and thus the indisputable expert of all things human.

“you might,” he assured them. They had grown a lot in the six years since he'd begun taking care of them. “you're already up to my chin.”

“But you're short,” they snickered.

“wow. harsh, kiddo. way to _look down_ on me.”

Their snickers bloomed into full laughter, their childish, high pitched voice blending with that of their friends. Next to him, Undyne and Papyrus groaned, while Asgore had a couple of chuckles at least. 

Kids just had a better sense of humour. 

“YOU COULD GROW AS TALL AS THE GREAT PAPYRUS, IF YOU MAKE SURE TO EAT YOUR VEGETABLES!” Papyrus told them. “AND ALWAYS DRINK YOUR MILK!”

“I drink my milk!” Frisk exclaimed. 

“Yeah, they had a whole bottle when they visited me, yo!” Monster Kid said, one of Frisk's closest friends. The other two began trying to trump each other on how much milk they were drinking while Sans and the other adult tried not to laugh at them. Only Asgore seemed a bit wistful at their behaviour. 

“Dad, can we use the telescope later?” Frisk asked when the laughter had died down, apropos of nothing. 

“is that what you wanna do as a sleepover activity?”

“Mhm,” they nodded. 

The other kids leaned forwards, all of them making pleading eyes. Or, in the case of the diamond head boy, a pleading head tilt. For a moment he made a strict face, pretending to seriously consider saying no, and the children practically trembled in their sitting positions. Except Frisk, who knew him better. 

“ok. i’ll set it up for you later. if we're lucky we might catch the meteor shower, it’s early this year,” he told them, giving them a relaxed grin and a wink. The tension drained from them and they cheered. 

“The pleiades!” Frisk shouted above the ruckus, eager to show off their knowledge. 

“close,” Sans said. “it’s called the perseids. the pleiades are a star cluster.”

“They sound the same,” Frisk complained. “I can't remember.”

“you'll get there,” he assured them. “you already know a lot for your age.”

“As much as you?” they wanted to know. 

“more than when i was that young.” He hadn’t had access to the kinds of books that Frisk had access to, back in the Underground. He was glad they got the opportunity to learn a lot though.

“Cool!” They seemed mollified now, turning back to chat with their friends. They noticed another group of children who were coming up on the lawn though, holding their own football. These ones were mostly human, four of them in total, but there was a single monster among them, a bunny with pale purple fur. 

When Frisk's friends noticed them looking, they turned to see what was up. 

The children stared at each other for a moment. 

“Do you wanna play?” one of the human kids finally asked, pointing at the football. 

Frisk and the others looked at each other and then they couldn't scramble up fast enough, shouting their agreement as they hurried to get moving again. Just as fast as they had barged in, they left. That was pretty normal. Frisk seemed to have almost as much energy as Papyrus did, and their friends weren't far behind. 

“Little rascals,” Undyne chuckled. “Never taking a break. I like it.”

“YES, THEY AREN'T LAZY AT ALL, UNLIKE SOME PEOPLE,” Papyrus agreed.

“it's good when they keep moving, means they'll fall asleep faster at night so i can relax,” Sans said, looking up at his brother with a teasing grin. 

“SANS!”

“what, that's basic parenting.”

“My wife and I used to say something similar,” Asgore threw in with a sheepish smile. 

“OH NO! DON'T SUPPORT HIS ATTITUDE!”

Sans was already laughing at Papyrus’ indignant tone. And underneath his bluster, Papyrus was of course smiling too. 

“It's crazy though,” Undyne eventually continued in a thoughtful manner. “Seeing them play like that. Monsters and humans… I didn't think they'd get along so fast.”

“BUT ISN'T IT A GOOD THING?” Papyrus wondered. 

“Of course it is!” Undyne insisted in a brief flare of energy before she immediately calmed down again. “It's just, we used to have so much anger towards them, you know? Some monsters still do. And not all humans like us that much either. But Frisk and their friends, they do it like it's nothing.”

“they're kids,” Sans said quietly. “from their perspective, they grew up in a world where monsters and humans have always lived together in freedom. it's easy for them because they don't know anything else.”

Nobody had any reply for that. 

Once, a long time ago, monsters had fallen down because they hadn't been able to deal with the horror of being trapped Underground. But their children grew up and didn't fall, because the caves hadn't just been their prison, they had been a home. Now, the reverse was happening. Centuries of imprisonment were not easy for the older monsters to leave behind, but for the youngest children it was merely history, something they would only know from books and stories, a dark age of the past that never touched them directly. 

And Frisk, most of all, would probably never understand the animosity between the species fully. 

How could they?

They had been raised by monsters, as a human, and as their parent Sans would have ensured regular contact to other humans even without the pressure of the social services agency. To deny his kid contact to their own people now that he could give it to them on the surface would have been unthinkable. So how would they understand why some argued that monsters and humans could never get along, when they were the living proof it could work? 

Sans wondered what Toriel would have said to that. 

He didn't carry her journal around anymore, only flipped through it occasionally to read her words and her jokes to remember her, just like Papyrus occasionally visited a small, green grave under a mountain. Sometimes, Asgore came over, and Sans had handed him the journal silently on multiple occasions so he could remember her as well. Sans suspected that Asgore had a much harder time dealing with Toriel's death still, given that he had known her longer. 

As for himself, he was able to think of her peacefully now. He was still sad to have lost such a good friend of course, and still mourned the fact that she had died in such a brutal way. 

But he was keeping his promise to her, every day, raising the child and protecting it as she had asked him. Making sure they not only survived, but got to have the best life he could possibly provide for them. There were always moments where he felt insecure or overwhelmed and there likely always would be. That was just part of being a parent. All in all though, he did feel that he was doing a good job with Frisk. 

He looked up, took in the sky again, that seemingly endless plane of blue and the sparse white clouds. He could hear Frisk telling a joke to their new friends, which warmed his bones down to their core. Then there was a new ruckus telling him Alphys and Mettaton and the canine squad must have arrived and Undyne and Papyrus were already rushing over to greet them while the kids lost their minds over the dogs. He should probably go over too; even Asgore had already left the blanket.

In a moment. 

It was such a peaceful and good feeling, just to be able to exist up here, surrounded by friends and family. There was little left to worry about. His brother and his child were happy, and the integration process was going well too. Even the irregularities with the timeline had ceased completely since the night he first noticed their absence. 

Time went on, as it should, straightforwardly and irrevocably into a future that looked nothing but bright.

When Sans stood up, he felt as though he was going to greet it.


End file.
